1
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Caballero Cerbon DA, Widmann J, Weuster-Botz D. Metabolic control analysis enabled the improvement of the L-cysteine production process with Escherichia coli. Appl Microbiol Biotechnol 2024; 108:108. [PMID: 38212968 PMCID: PMC10784400 DOI: 10.1007/s00253-023-12928-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2023] [Revised: 09/14/2023] [Accepted: 09/30/2023] [Indexed: 01/13/2024]
Abstract
L-cysteine is an amino acid with relevance to the pharmaceutical, food, feed, and cosmetic industry. The environmental and societal impact of its chemical production has led to the development of more sustainable fermentative L-cysteine production processes with engineered E. coli based on glucose and thiosulfate as sulphur source. Still, most of the published processes show low yields. For the identification of further metabolic engineering targets, engineered E. coli cells were withdrawn from a fed-batch production process, followed by in vivo metabolic control analysis (MCA) based on the data of short-term perturbation experiments, metabolomics (LC-MS), and thermodynamic flux analysis (TFA). In vivo MCA indicated that the activities of the L-cysteine synthases of the cells withdrawn from the production process might be limiting, and we hypothesised that the L-cysteine precursor O-acetylserine (OAS) might be exported from the cells faster than it took to transform OAS into L-cysteine. By increasing the expression of the L-cysteine synthases, either sulfocysteine synthase or L-cysteine synthase, which transform OAS into L-cysteine, an improvement of up to 70% in specific L-cysteine productivity and up to 47% in the final L-cysteine concentration was achieved in standardised fed-batch processes thereby increasing the yield on glucose by more than 85 to 9.2% (w/w). KEY POINTS: • Metabolic control analysis was applied to analyse L-cysteine production with E. coli • OAS export was faster than its transformation to L-cysteine • Overexpression of L-cysteine synthases improved L-cysteine productivity and yield.
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Affiliation(s)
- Daniel Alejandro Caballero Cerbon
- Chair of Biochemical Engineering, School of Engineering and Design, Technical University of Munich, Boltzmannstr. 15, 85748, Garching, Germany
| | - Jeremias Widmann
- Chair of Biochemical Engineering, School of Engineering and Design, Technical University of Munich, Boltzmannstr. 15, 85748, Garching, Germany
| | - Dirk Weuster-Botz
- Chair of Biochemical Engineering, School of Engineering and Design, Technical University of Munich, Boltzmannstr. 15, 85748, Garching, Germany.
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2
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Wang L, Guo Y, Shen Y, Yang K, Cai X, Zhang B, Liu Z, Zheng Y. Microbial production of sulfur-containing amino acids using metabolically engineered Escherichia coli. Biotechnol Adv 2024; 73:108353. [PMID: 38593935 DOI: 10.1016/j.biotechadv.2024.108353] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2023] [Revised: 04/03/2024] [Accepted: 04/03/2024] [Indexed: 04/11/2024]
Abstract
L-Cysteine and L-methionine, as the only two sulfur-containing amino acids among the canonical 20 amino acids, possess distinct characteristics and find wide-ranging industrial applications. The use of different organisms for fermentative production of L-cysteine and L-methionine is gaining increasing attention, with Escherichia coli being extensively studied as the preferred strain. This preference is due to its ability to grow rapidly in cost-effective media, its robustness for industrial processes, the well-characterized metabolism, and the availability of molecular tools for genetic engineering. This review focuses on the genetic and molecular mechanisms involved in the production of these sulfur-containing amino acids in E. coli. Additionally, we systematically summarize the metabolic engineering strategies employed to enhance their production, including the identification of new targets, modulation of metabolic fluxes, modification of transport systems, dynamic regulation strategies, and optimization of fermentation conditions. The strategies and design principles discussed in this review hold the potential to facilitate the development of strain and process engineering for direct fermentation of sulfur-containing amino acids.
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Affiliation(s)
- Lijuan Wang
- The National and Local Joint Engineering Research Center for Biomanufacturing of Chiral Chemicals, Zhejiang University of Technology, Hangzhou, Zhejiang 310014, PR China; Key Laboratory of Bioorganic Synthesis of Zhejiang Province, College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, Zhejiang 310014, PR China
| | - Yingying Guo
- The National and Local Joint Engineering Research Center for Biomanufacturing of Chiral Chemicals, Zhejiang University of Technology, Hangzhou, Zhejiang 310014, PR China; Key Laboratory of Bioorganic Synthesis of Zhejiang Province, College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, Zhejiang 310014, PR China
| | - Yizhou Shen
- The National and Local Joint Engineering Research Center for Biomanufacturing of Chiral Chemicals, Zhejiang University of Technology, Hangzhou, Zhejiang 310014, PR China; Key Laboratory of Bioorganic Synthesis of Zhejiang Province, College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, Zhejiang 310014, PR China
| | - Kun Yang
- The National and Local Joint Engineering Research Center for Biomanufacturing of Chiral Chemicals, Zhejiang University of Technology, Hangzhou, Zhejiang 310014, PR China; Key Laboratory of Bioorganic Synthesis of Zhejiang Province, College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, Zhejiang 310014, PR China
| | - Xue Cai
- The National and Local Joint Engineering Research Center for Biomanufacturing of Chiral Chemicals, Zhejiang University of Technology, Hangzhou, Zhejiang 310014, PR China; Key Laboratory of Bioorganic Synthesis of Zhejiang Province, College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, Zhejiang 310014, PR China
| | - Bo Zhang
- The National and Local Joint Engineering Research Center for Biomanufacturing of Chiral Chemicals, Zhejiang University of Technology, Hangzhou, Zhejiang 310014, PR China; Key Laboratory of Bioorganic Synthesis of Zhejiang Province, College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, Zhejiang 310014, PR China
| | - Zhiqiang Liu
- The National and Local Joint Engineering Research Center for Biomanufacturing of Chiral Chemicals, Zhejiang University of Technology, Hangzhou, Zhejiang 310014, PR China; Key Laboratory of Bioorganic Synthesis of Zhejiang Province, College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, Zhejiang 310014, PR China.
| | - Yuguo Zheng
- The National and Local Joint Engineering Research Center for Biomanufacturing of Chiral Chemicals, Zhejiang University of Technology, Hangzhou, Zhejiang 310014, PR China; Key Laboratory of Bioorganic Synthesis of Zhejiang Province, College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, Zhejiang 310014, PR China
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3
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Chen Z, Yu S, Liu J, Guo L, Wu T, Duan P, Yan D, Huang C, Huo Y. Concentration Recognition-Based Auto-Dynamic Regulation System (CRUISE) Enabling Efficient Production of Higher Alcohols. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2024; 11:e2310215. [PMID: 38626358 PMCID: PMC11187965 DOI: 10.1002/advs.202310215] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/26/2023] [Revised: 03/12/2024] [Indexed: 04/18/2024]
Abstract
Microbial factories lacking the ability of dynamically regulating the pathway enzymes overexpression, according to in situ metabolite concentrations, are suboptimal, especially when the metabolic intermediates are competed by growth and chemical production. The production of higher alcohols (HAs), which hijacks the amino acids (AAs) from protein biosynthesis, minimizes the intracellular concentration of AAs and thus inhibits the host growth. To balance the resource allocation and maintain stable AA flux, this work utilizes AA-responsive transcriptional attenuator ivbL and HA-responsive transcriptional activator BmoR to establish a concentration recognition-based auto-dynamic regulation system (CRUISE). This system ultimately maintains the intracellular homeostasis of AA and maximizes the production of HA. It is demonstrated that ivbL-driven enzymes overexpression can dynamically regulate the AA-to-HA conversion while BmoR-driven enzymes overexpression can accelerate the AA biosynthesis during the HA production in a feedback activation mode. The AA flux in biosynthesis and conversion pathways is balanced via the intracellular AA concentration, which is vice versa stabilized by the competition between AA biosynthesis and conversion. The CRUISE, further aided by scaffold-based self-assembly, enables 40.4 g L-1 of isobutanol production in a bioreactor. Taken together, CRUISE realizes robust HA production and sheds new light on the dynamic flux control during the process of chemical production.
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Affiliation(s)
- Zhenya Chen
- Key Laboratory of Molecular Medicine and BiotherapyAerospace Center HospitalSchool of Life ScienceBeijing Institute of TechnologyHaidian DistrictNo. 5 South Zhongguancun StreetBeijing100081China
- Tangshan Research InstituteBeijing Institute of Technology, No. 57, South Jianshe Road, Lubei DistrictTangshanHebei063000China
| | - Shengzhu Yu
- Key Laboratory of Molecular Medicine and BiotherapyAerospace Center HospitalSchool of Life ScienceBeijing Institute of TechnologyHaidian DistrictNo. 5 South Zhongguancun StreetBeijing100081China
| | - Jing Liu
- Key Laboratory of Molecular Medicine and BiotherapyAerospace Center HospitalSchool of Life ScienceBeijing Institute of TechnologyHaidian DistrictNo. 5 South Zhongguancun StreetBeijing100081China
| | - Liwei Guo
- Key Laboratory of Molecular Medicine and BiotherapyAerospace Center HospitalSchool of Life ScienceBeijing Institute of TechnologyHaidian DistrictNo. 5 South Zhongguancun StreetBeijing100081China
| | - Tong Wu
- Key Laboratory of Molecular Medicine and BiotherapyAerospace Center HospitalSchool of Life ScienceBeijing Institute of TechnologyHaidian DistrictNo. 5 South Zhongguancun StreetBeijing100081China
| | - Peifeng Duan
- Key Laboratory of Molecular Medicine and BiotherapyAerospace Center HospitalSchool of Life ScienceBeijing Institute of TechnologyHaidian DistrictNo. 5 South Zhongguancun StreetBeijing100081China
| | - Dongli Yan
- Key Laboratory of Molecular Medicine and BiotherapyAerospace Center HospitalSchool of Life ScienceBeijing Institute of TechnologyHaidian DistrictNo. 5 South Zhongguancun StreetBeijing100081China
| | - Chaoyong Huang
- Key Laboratory of Molecular Medicine and BiotherapyAerospace Center HospitalSchool of Life ScienceBeijing Institute of TechnologyHaidian DistrictNo. 5 South Zhongguancun StreetBeijing100081China
| | - Yi‐Xin Huo
- Key Laboratory of Molecular Medicine and BiotherapyAerospace Center HospitalSchool of Life ScienceBeijing Institute of TechnologyHaidian DistrictNo. 5 South Zhongguancun StreetBeijing100081China
- Tangshan Research InstituteBeijing Institute of Technology, No. 57, South Jianshe Road, Lubei DistrictTangshanHebei063000China
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4
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Smirnova G, Tyulenev A, Sutormina L, Kalashnikova T, Muzyka N, Ushakov V, Samoilova Z, Oktyabrsky O. Regulation of Cysteine Homeostasis and Its Effect on Escherichia coli Sensitivity to Ciprofloxacin in LB Medium. Int J Mol Sci 2024; 25:4424. [PMID: 38674008 PMCID: PMC11050555 DOI: 10.3390/ijms25084424] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2024] [Revised: 04/15/2024] [Accepted: 04/16/2024] [Indexed: 04/28/2024] Open
Abstract
Cysteine and its derivatives, including H2S, can influence bacterial virulence and sensitivity to antibiotics. In minimal sulfate media, H2S is generated under stress to prevent excess cysteine and, together with incorporation into glutathione and export into the medium, is a mechanism of cysteine homeostasis. Here, we studied the features of cysteine homeostasis in LB medium, where the main source of sulfur is cystine, whose import can create excess cysteine inside cells. We used mutants in the mechanisms of cysteine homeostasis and a set of microbiological and biochemical methods, including the real-time monitoring of sulfide and oxygen, the determination of cysteine and glutathione (GSH), and the expression of the Fur, OxyR, and SOS regulons genes. During normal growth, the parental strain generated H2S when switching respiration to another substrate. The mutations affected the onset time, the intensity and duration of H2S production, cysteine and glutathione levels, bacterial growth and respiration rates, and the induction of defense systems. Exposure to chloramphenicol and high doses of ciprofloxacin increased cysteine content and GSH synthesis. A high inverse relationship between log CFU/mL and bacterial growth rate before ciprofloxacin addition was revealed. The study points to the important role of maintaining cysteine homeostasis during normal growth and antibiotic exposure in LB medium.
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Affiliation(s)
- Galina Smirnova
- Institute of Ecology and Genetics of Microorganisms, Perm Federal Research Center, Russian Academy of Sciences, Goleva 13, 614081 Perm, Russia; (A.T.); (L.S.); (T.K.); (N.M.); (V.U.); (Z.S.); (O.O.)
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5
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Wang W, Xiang Y, Yin G, Hu S, Cheng J, Chen J, Du G, Kang Z, Wang Y. Construction of 5-Aminolevulinic Acid Microbial Cell Factories through Identification of Novel Synthases and Metabolic Pathway Screens and Transporters. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2024; 72:8006-8017. [PMID: 38554273 DOI: 10.1021/acs.jafc.4c00903] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/01/2024]
Abstract
5-Aminolevulinic acid (5-ALA) plays a pivotal role in the biosynthesis of heme and chlorophyll and has garnered great attention for its agricultural applications. This study explores the multifaceted construction of 5-ALA microbial cell factories. Evolutionary analysis-guided screening identified a novel 5-ALA synthase from Sphingobium amiense as the best synthase. An sRNA library facilitated global gene screening that demonstrated that trpC and ilvA repression enhanced 5-ALA production by 74.3% and 102%, respectively. Subsequently, efflux of 5-ALA by the transporter Gdx increased 5-ALA biosynthesis by 25.7%. To mitigate oxidative toxicity, DNA-binding proteins from starved cells were employed, enhancing cell density and 5-ALA titer by 21.1 and 4.1%, respectively. Combining these strategies resulted in an Escherichia coli strain that produced 5-ALA to 1.51 g·L-1 in shake flask experiments and 6.19 g·L-1 through fed-batch fermentation. This study broadens the repertoire of available 5-ALA synthases and transporters and provides a new platform for optimizing 5-ALA bioproduction.
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Affiliation(s)
- Wenqiu Wang
- The Science Center for Future Foods, Jiangnan University, Wuxi 214122, China
- The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi 214122, China
- Jiaxing Institute of Future Food, Jiaxing 314050, China
| | - Yulong Xiang
- The Science Center for Future Foods, Jiangnan University, Wuxi 214122, China
- The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi 214122, China
| | - Guobin Yin
- The Science Center for Future Foods, Jiangnan University, Wuxi 214122, China
- The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi 214122, China
| | - Shan Hu
- The Science Center for Future Foods, Jiangnan University, Wuxi 214122, China
- The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi 214122, China
- Jiaxing Institute of Future Food, Jiaxing 314050, China
| | - Jian Cheng
- The Science Center for Future Foods, Jiangnan University, Wuxi 214122, China
- The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi 214122, China
| | - Jian Chen
- The Science Center for Future Foods, Jiangnan University, Wuxi 214122, China
- The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi 214122, China
| | - Guocheng Du
- The Science Center for Future Foods, Jiangnan University, Wuxi 214122, China
- The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi 214122, China
| | - Zhen Kang
- The Science Center for Future Foods, Jiangnan University, Wuxi 214122, China
- The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi 214122, China
- The Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi 214122, China
| | - Yang Wang
- The Science Center for Future Foods, Jiangnan University, Wuxi 214122, China
- The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi 214122, China
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6
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Warneke R, Herzberg C, Daniel R, Hormes B, Stülke J. Control of three-carbon amino acid homeostasis by promiscuous importers and exporters in Bacillus subtilis: role of the "sleeping beauty" amino acid exporters. mBio 2024; 15:e0345623. [PMID: 38470260 PMCID: PMC11005379 DOI: 10.1128/mbio.03456-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2023] [Accepted: 02/13/2024] [Indexed: 03/13/2024] Open
Abstract
The Gram-positive model bacterium Bacillus subtilis can acquire amino acids by import, de novo biosynthesis, or degradation of proteins and peptides. The accumulation of several amino acids inhibits the growth of B. subtilis, probably due to misincorporation into cellular macromolecules such as proteins or peptidoglycan or due to interference with other amino acid biosynthetic pathways. Here, we studied the adaptation of B. subtilis to toxic concentrations of the three-carbon amino acids L-alanine, β-alanine, and 2,3-diaminopropionic acid, as well as the two-carbon amino acid glycine. Resistance to the non-proteinogenic amino acid β-alanine, which is a precursor for coenzyme A biosynthesis, is achieved by mutations that either activate a cryptic amino acid exporter, AexA (previously YdeD), or inactivate the amino acid importers AimA, AimB (previously YbxG), and BcaP. The aexA gene is very poorly expressed under most conditions studied. However, mutations affecting the transcription factor AerA (previously YdeC) can result in strong constitutive aexA expression. AexA is the first characterized member of a group of amino acid exporters in B. subtilis, which are all very poorly expressed. Therefore, we suggest to call this group "sleeping beauty amino acid exporters." 2,3-Diaminopropionic acid can also be exported by AexA, and this amino acid also seems to be a natural substrate of AerA/AexA, as it can cause a slight but significant induction of aexA expression, and AexA also provides some natural resistance toward 2,3-diaminopropionic acid. Moreover, our work shows how low-specificity amino acid transporters contribute to amino acid homeostasis in B. subtilis.IMPORTANCEEven though Bacillus subtilis is one of the most-studied bacteria, amino acid homeostasis in this organism is not fully understood. We have identified import and export systems for the C2 and C3 amino acids. Our work demonstrates that the responsible amino acid permeases contribute in a rather promiscuitive way to amino acid uptake. In addition, we have discovered AexA, the first member of a group of very poorly expressed amino acid exporters in B. subtilis that we call "sleeping beauty amino acid exporters." The expression of these transporters is typically triggered by mutations in corresponding regulator genes that are acquired upon exposure to toxic amino acids. These exporters are ubiquitous in all domains of life. It is tempting to speculate that many of them are not expressed until the cells experience selective pressure by toxic compounds, and they protect the cells from rare but potentially dangerous encounters with such compounds.
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Affiliation(s)
- Robert Warneke
- Department of General Microbiology, Institute for Microbiology and Genetics, GZMB, Georg-August-University, Göttingen, Germany
| | - Christina Herzberg
- Department of General Microbiology, Institute for Microbiology and Genetics, GZMB, Georg-August-University, Göttingen, Germany
| | - Richard Daniel
- Center for Bacterial Cell Biology, Biosciences Institute, Medical Faculty, Newcastle University, Newcastle Upon Tyne, United Kingdom
| | - Björn Hormes
- Department of General Microbiology, Institute for Microbiology and Genetics, GZMB, Georg-August-University, Göttingen, Germany
| | - Jörg Stülke
- Department of General Microbiology, Institute for Microbiology and Genetics, GZMB, Georg-August-University, Göttingen, Germany
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7
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Caballero Cerbon DA, Gebhard L, Dokuyucu R, Ertl T, Härtl S, Mazhar A, Weuster-Botz D. Challenges and Advances in the Bioproduction of L-Cysteine. Molecules 2024; 29:486. [PMID: 38257399 PMCID: PMC10821248 DOI: 10.3390/molecules29020486] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2023] [Revised: 01/15/2024] [Accepted: 01/17/2024] [Indexed: 01/24/2024] Open
Abstract
L-cysteine is a proteogenic amino acid with many applications in the pharmaceutical, food, animal feed, and cosmetic industries. Due to safety and environmental issues in extracting L-cysteine from animal hair and feathers, the fermentative production of L-cysteine offers an attractive alternative using renewable feedstocks. Strategies to improve microbial production hosts like Pantoea ananatis, Corynebacterium glutamicum, Pseudomonas sp., and Escherichia coli are summarized. Concerning the metabolic engineering strategies, the overexpression of feedback inhibition-insensitive L-serine O-acetyltransferase and weakening the degradation of L-cysteine through the removal of L-cysteine desulfhydrases are crucial adjustments. The overexpression of L-cysteine exporters is vital to overcome the toxicity caused by intracellular accumulating L-cysteine. In addition, we compiled the process engineering aspects for the bioproduction of L-cysteine. Utilizing the energy-efficient sulfur assimilation pathway via thiosulfate, fermenting cheap carbon sources, designing scalable, fed-batch processes with individual feedings of carbon and sulfur sources, and implementing efficient purification techniques are essential for the fermentative production of L-cysteine on an industrial scale.
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Affiliation(s)
- Daniel Alejandro Caballero Cerbon
- Chair of Biochemical Engineering, TUM School of Engineering and Design, Technical University of Munich, Boltzmannstraße 15, D-85748 Garching, Germany;
| | - Leon Gebhard
- TUM School of Engineering and Design, Technical University of Munich, Boltzmannstraße 15, D-85748 Garching, Germany
| | - Ruveyda Dokuyucu
- TUM Campus Straubing for Biotechnology and Sustainability, Technical University of Munich, Petersgasse 5, D-94315 Straubing, Germany; (R.D.); (T.E.); (S.H.)
| | - Theresa Ertl
- TUM Campus Straubing for Biotechnology and Sustainability, Technical University of Munich, Petersgasse 5, D-94315 Straubing, Germany; (R.D.); (T.E.); (S.H.)
| | - Sophia Härtl
- TUM Campus Straubing for Biotechnology and Sustainability, Technical University of Munich, Petersgasse 5, D-94315 Straubing, Germany; (R.D.); (T.E.); (S.H.)
| | - Ayesha Mazhar
- TUM Campus Straubing for Biotechnology and Sustainability, Technical University of Munich, Petersgasse 5, D-94315 Straubing, Germany; (R.D.); (T.E.); (S.H.)
| | - Dirk Weuster-Botz
- Chair of Biochemical Engineering, TUM School of Engineering and Design, Technical University of Munich, Boltzmannstraße 15, D-85748 Garching, Germany;
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8
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Smirnova GV, Tyulenev AV, Bezmaternykh KV, Muzyka NG, Ushakov VY, Oktyabrsky ON. Phosphate starvation is accompanied by disturbance of intracellular cysteine homeostasis in Escherichia coli. Res Microbiol 2023; 174:104108. [PMID: 37516155 DOI: 10.1016/j.resmic.2023.104108] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2023] [Revised: 07/19/2023] [Accepted: 07/24/2023] [Indexed: 07/31/2023]
Abstract
Metabolic rearrangements that occur during depletion of essential nutrients can lead to accumulation of potentially dangerous metabolites. Here we showed that depletion of phosphate (Pi), accompanied by a sharp inhibition of growth and respiration, caused a transient excess of intracellular cysteine due to a decrease in the rate of protein synthesis. High cysteine level can be dangerous due to its ability to produce ROS and reduce Fe3+ to Fenton-reactive Fe2+. To prevent these negative effects, excess cysteine was mainly incorporated into glutathione (GSH), the intracellular level of which increased by 3 times, and was also exported to the medium and partially degraded to form H2S with participation of 3-mercaptopyruvate sulfotransferase (3MST). The addition of Pi to starving cells led to a sharp recovery of respiration and growth, GSH efflux into the medium and K+ influx into the cells. A pronounced coupling of Pi, GSH, and K+ fluxes was shown upon Pi depletion and addition, which may be necessary to maintain the ionic balance in the cytoplasm. We suggest that processes aimed at restoring cysteine homeostasis may be an integral part of the universal response to stress under different types of stress and for different types of bacteria.
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Affiliation(s)
- Galina V Smirnova
- Institute of Ecology and Genetics of Microorganisms, Perm Federal Research Center, Russian Academy of Sciences, ul. Goleva 13, Perm, 614081, Russia.
| | - Aleksey V Tyulenev
- Institute of Ecology and Genetics of Microorganisms, Perm Federal Research Center, Russian Academy of Sciences, ul. Goleva 13, Perm, 614081, Russia.
| | - Kseniya V Bezmaternykh
- Institute of Ecology and Genetics of Microorganisms, Perm Federal Research Center, Russian Academy of Sciences, ul. Goleva 13, Perm, 614081, Russia.
| | - Nadezda G Muzyka
- Institute of Ecology and Genetics of Microorganisms, Perm Federal Research Center, Russian Academy of Sciences, ul. Goleva 13, Perm, 614081, Russia.
| | - Vadim Y Ushakov
- Institute of Ecology and Genetics of Microorganisms, Perm Federal Research Center, Russian Academy of Sciences, ul. Goleva 13, Perm, 614081, Russia.
| | - Oleg N Oktyabrsky
- Institute of Ecology and Genetics of Microorganisms, Perm Federal Research Center, Russian Academy of Sciences, ul. Goleva 13, Perm, 614081, Russia.
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9
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Chowdhury F, Findlay BL. Fitness Costs of Antibiotic Resistance Impede the Evolution of Resistance to Other Antibiotics. ACS Infect Dis 2023; 9:1834-1845. [PMID: 37726252 PMCID: PMC10581211 DOI: 10.1021/acsinfecdis.3c00156] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2023] [Indexed: 09/21/2023]
Abstract
Antibiotic resistance is a major threat to global health, claiming the lives of millions every year. With a nearly dry antibiotic development pipeline, novel strategies are urgently needed to combat resistant pathogens. One emerging strategy is the use of sequential antibiotic therapy, postulated to reduce the rate at which antibiotic resistance evolves. Here, we use the soft agar gradient evolution (SAGE) system to carry out high-throughput in vitro bacterial evolution against antibiotic pressure. We find that evolution of resistance to the antibiotic chloramphenicol (CHL) severely affects bacterial fitness, slowing the rate at which resistance to the antibiotics nitrofurantoin and streptomycin emerges. In vitro acquisition of compensatory mutations in the CHL-resistant cells markedly improves fitness and nitrofurantoin adaptation rates but fails to restore rates to wild-type levels against streptomycin. Genome sequencing reveals distinct evolutionary paths to resistance in fitness-impaired populations, suggesting resistance trade-offs in favor of mitigation of fitness costs. We show that the speed of bacterial fronts in SAGE plates is a reliable indicator of adaptation rates and evolutionary trajectories to resistance. Identification of antibiotics whose mutational resistance mechanisms confer stable impairments may help clinicians prescribe sequential antibiotic therapies that are less prone to resistance evolution.
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Affiliation(s)
- Farhan
R. Chowdhury
- Department
of Biology, Concordia University, Montréal, Québec H4B 1R6, Canada
| | - Brandon L. Findlay
- Department
of Biology, Concordia University, Montréal, Québec H4B 1R6, Canada
- Department
of Chemistry and Biochemistry, Concordia
University, Montréal, Québec H4B 1R6, Canada
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10
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Abstract
The metabolism of a bacterial cell stretches beyond its boundaries, often connecting with the metabolism of other cells to form extended metabolic networks that stretch across communities, and even the globe. Among the least intuitive metabolic connections are those involving cross-feeding of canonically intracellular metabolites. How and why are these intracellular metabolites externalized? Are bacteria simply leaky? Here I consider what it means for a bacterium to be leaky, and I review mechanisms of metabolite externalization from the context of cross-feeding. Despite common claims, diffusion of most intracellular metabolites across a membrane is unlikely. Instead, passive and active transporters are likely involved, possibly purging excess metabolites as part of homeostasis. Re-acquisition of metabolites by a producer limits the opportunities for cross-feeding. However, a competitive recipient can stimulate metabolite externalization and initiate a positive-feedback loop of reciprocal cross-feeding.
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Affiliation(s)
- James B McKinlay
- Department of Biology, Indiana University, Bloomington, Indiana, USA;
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11
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Moeller FU, Herbold CW, Schintlmeister A, Mooshammer M, Motti C, Glasl B, Kitzinger K, Behnam F, Watzka M, Schweder T, Albertsen M, Richter A, Webster NS, Wagner M. Taurine as a key intermediate for host-symbiont interaction in the tropical sponge Ianthella basta. THE ISME JOURNAL 2023; 17:1208-1223. [PMID: 37188915 PMCID: PMC10356861 DOI: 10.1038/s41396-023-01420-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/23/2022] [Revised: 04/14/2023] [Accepted: 04/20/2023] [Indexed: 05/17/2023]
Abstract
Marine sponges are critical components of marine benthic fauna assemblages, where their filter-feeding and reef-building capabilities provide bentho-pelagic coupling and crucial habitat. As potentially the oldest representation of a metazoan-microbe symbiosis, they also harbor dense, diverse, and species-specific communities of microbes, which are increasingly recognized for their contributions to dissolved organic matter (DOM) processing. Recent omics-based studies of marine sponge microbiomes have proposed numerous pathways of dissolved metabolite exchange between the host and symbionts within the context of the surrounding environment, but few studies have sought to experimentally interrogate these pathways. By using a combination of metaproteogenomics and laboratory incubations coupled with isotope-based functional assays, we showed that the dominant gammaproteobacterial symbiont, 'Candidatus Taurinisymbion ianthellae', residing in the marine sponge, Ianthella basta, expresses a pathway for the import and dissimilation of taurine, a ubiquitously occurring sulfonate metabolite in marine sponges. 'Candidatus Taurinisymbion ianthellae' incorporates taurine-derived carbon and nitrogen while, at the same time, oxidizing the dissimilated sulfite into sulfate for export. Furthermore, we found that taurine-derived ammonia is exported by the symbiont for immediate oxidation by the dominant ammonia-oxidizing thaumarchaeal symbiont, 'Candidatus Nitrosospongia ianthellae'. Metaproteogenomic analyses also suggest that 'Candidatus Taurinisymbion ianthellae' imports DMSP and possesses both pathways for DMSP demethylation and cleavage, enabling it to use this compound as a carbon and sulfur source for biomass, as well as for energy conservation. These results highlight the important role of biogenic sulfur compounds in the interplay between Ianthella basta and its microbial symbionts.
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Affiliation(s)
- Florian U Moeller
- Centre for Microbiology and Environmental Systems Science, Division of Microbial Ecology, University of Vienna, Vienna, Austria
| | - Craig W Herbold
- Centre for Microbiology and Environmental Systems Science, Division of Microbial Ecology, University of Vienna, Vienna, Austria
| | - Arno Schintlmeister
- Centre for Microbiology and Environmental Systems Science, Division of Microbial Ecology, University of Vienna, Vienna, Austria
- Large-Instrument Facility for Environmental and Isotope Mass Spectrometry, Centre for Microbiology and Environmental Systems Science, University of Vienna, Vienna, Austria
| | - Maria Mooshammer
- Centre for Microbiology and Environmental Systems Science, Division of Microbial Ecology, University of Vienna, Vienna, Austria
| | - Cherie Motti
- Australian Institute of Marine Science, Townsville, QLD, Australia
| | - Bettina Glasl
- Centre for Microbiology and Environmental Systems Science, Division of Microbial Ecology, University of Vienna, Vienna, Austria
| | - Katharina Kitzinger
- Centre for Microbiology and Environmental Systems Science, Division of Microbial Ecology, University of Vienna, Vienna, Austria
| | - Faris Behnam
- Centre for Microbiology and Environmental Systems Science, Division of Microbial Ecology, University of Vienna, Vienna, Austria
| | - Margarete Watzka
- Centre for Microbiology and Environmental Systems Science, Division of Terrestrial Ecosystem Research, University of Vienna, Vienna, Austria
| | - Thomas Schweder
- Institute of Marine Biotechnology e.V., Greifswald, Germany
- Institute of Pharmacy, Pharmaceutical Biotechnology, University of Greifswald, Greifswald, Germany
| | - Mads Albertsen
- Center for Microbial Communities, Department of Chemistry and Bioscience, Aalborg University, Aalborg, Denmark
| | - Andreas Richter
- Centre for Microbiology and Environmental Systems Science, Division of Terrestrial Ecosystem Research, University of Vienna, Vienna, Austria
| | - Nicole S Webster
- Australian Institute of Marine Science, Townsville, QLD, Australia
- Australian Centre for Ecogenomics, School of Chemistry and Molecular Biosciences, University of Queensland, St Lucia, St Lucia, QLD, Australia
- Australian Antarctic Division, Kingston, TAS, Australia
| | - Michael Wagner
- Centre for Microbiology and Environmental Systems Science, Division of Microbial Ecology, University of Vienna, Vienna, Austria.
- Large-Instrument Facility for Environmental and Isotope Mass Spectrometry, Centre for Microbiology and Environmental Systems Science, University of Vienna, Vienna, Austria.
- Center for Microbial Communities, Department of Chemistry and Bioscience, Aalborg University, Aalborg, Denmark.
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12
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Katsube S, Sakai K, Ando T, Tobe R, Yoneyama H. l-Alanine Exporter AlaE Functions as One of the d-Alanine Exporters in Escherichia coli. Int J Mol Sci 2023; 24:10242. [PMID: 37373388 DOI: 10.3390/ijms241210242] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2023] [Accepted: 06/12/2023] [Indexed: 06/29/2023] Open
Abstract
d-amino acids have recently been found to be present in the extracellular milieu at millimolar levels and are therefore assumed to play a physiological function. However, the pathway (or potential pathways) by which these d-amino acids are secreted remains unknown. Recently, Escherichia coli has been found to possess one or more energy-dependent d-alanine export systems. To gain insight into these systems, we developed a novel screening system in which cells expressing a putative d-alanine exporter could support the growth of d-alanine auxotrophs in the presence of l-alanyl-l-alanine. In the initial screening, five d-alanine exporter candidates, AlaE, YmcD, YciC, YraM, and YidH, were identified. Transport assays of radiolabeled d-alanine in cells expressing these candidates indicated that YciC and AlaE resulted in lower intracellular levels of d-alanine. Further detailed transport assays of AlaE in intact cells showed that it exports d-alanine in an expression-dependent manner. In addition, the growth constraints on cells in the presence of 90 mM d-alanine were mitigated by the overexpression of AlaE, implying that AlaE could export free d-alanine in addition to l-alanine under conditions in which intracellular d/l-alanine levels are raised. This study also shows, for the first time, that YciC could function as a d-alanine exporter in intact cells.
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Affiliation(s)
- Satoshi Katsube
- Department of Cell Physiology and Molecular Biophysics, Center for Membrane Protein Research, School of Medicine, Texas Tech University Health Sciences Center, Lubbock, TX 79430, USA
| | - Keiichiro Sakai
- Laboratory of Animal Microbiology, Department of Animal Science, Graduate School of Agricultural Science, Tohoku University, 468-1, Aramaki Aza Aoba, Aoba-ku, Sendai 980-0845, Japan
| | - Tasuke Ando
- Laboratory of Animal Microbiology, Department of Animal Science, Graduate School of Agricultural Science, Tohoku University, 468-1, Aramaki Aza Aoba, Aoba-ku, Sendai 980-0845, Japan
| | - Ryuta Tobe
- Laboratory of Animal Microbiology, Department of Animal Science, Graduate School of Agricultural Science, Tohoku University, 468-1, Aramaki Aza Aoba, Aoba-ku, Sendai 980-0845, Japan
| | - Hiroshi Yoneyama
- Laboratory of Animal Microbiology, Department of Animal Science, Graduate School of Agricultural Science, Tohoku University, 468-1, Aramaki Aza Aoba, Aoba-ku, Sendai 980-0845, Japan
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13
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Zhang B, Yang H, Wu Z, Pan J, Li S, Chen L, Cai X, Liu Z, Zheng Y. Spatiotemporal Gene Expression by a Genetic Circuit for Chemical Production in Escherichia coli. ACS Synth Biol 2023; 12:768-779. [PMID: 36821871 DOI: 10.1021/acssynbio.2c00568] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/25/2023]
Abstract
Gene expression in spatiotemporal distribution improves the ability of cells to respond to changing environments. For microbial cell factories in artificial environments, reconstruction of the target compound's biosynthetic pathway in a new spatiotemporal dimension/scale promotes the production of chemicals. Here, a genetic circuit based on the Esa quorum sensing and lac operon was designed to achieve the dynamic temporal gene expression. Meanwhile, the pathway was regulated by an l-cysteine-specific sensor and relocalized to the plasma membrane for further flux enhancement to l-cysteine and toxicity reduction on a spatial scale. Finally, the integrated spatiotemporal regulation circuit for l-cysteine biosynthesis enabled a 14.16 g/L l-cysteine yield in Escherichia coli. Furthermore, this spatiotemporal regulation circuit was also applied in our previously constructed engineered strain for pantothenic acid, methionine, homoserine, and 2-aminobutyric acid production, and the titer increased by 29, 33, 28, and 41%, respectively. These results highlighted the applicability of our spatiotemporal regulation circuit to enhance the performance of microbial cell factories.
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Affiliation(s)
- Bo Zhang
- The National and Local Joint Engineering Research Center for Biomanufacturing of Chiral Chemicals, Zhejiang University of Technology, Hangzhou 310014, P. R. China.,Key Laboratory of Bioorganic Synthesis of Zhejiang Province, College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou 310014, P. R. China
| | - Hui Yang
- The National and Local Joint Engineering Research Center for Biomanufacturing of Chiral Chemicals, Zhejiang University of Technology, Hangzhou 310014, P. R. China.,Key Laboratory of Bioorganic Synthesis of Zhejiang Province, College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou 310014, P. R. China
| | - Zidan Wu
- The National and Local Joint Engineering Research Center for Biomanufacturing of Chiral Chemicals, Zhejiang University of Technology, Hangzhou 310014, P. R. China.,Key Laboratory of Bioorganic Synthesis of Zhejiang Province, College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou 310014, P. R. China
| | - Jiayuan Pan
- The National and Local Joint Engineering Research Center for Biomanufacturing of Chiral Chemicals, Zhejiang University of Technology, Hangzhou 310014, P. R. China.,Key Laboratory of Bioorganic Synthesis of Zhejiang Province, College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou 310014, P. R. China
| | - Shirong Li
- The National and Local Joint Engineering Research Center for Biomanufacturing of Chiral Chemicals, Zhejiang University of Technology, Hangzhou 310014, P. R. China.,Key Laboratory of Bioorganic Synthesis of Zhejiang Province, College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou 310014, P. R. China
| | - Lifeng Chen
- The National and Local Joint Engineering Research Center for Biomanufacturing of Chiral Chemicals, Zhejiang University of Technology, Hangzhou 310014, P. R. China.,Key Laboratory of Bioorganic Synthesis of Zhejiang Province, College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou 310014, P. R. China
| | - Xue Cai
- The National and Local Joint Engineering Research Center for Biomanufacturing of Chiral Chemicals, Zhejiang University of Technology, Hangzhou 310014, P. R. China.,Key Laboratory of Bioorganic Synthesis of Zhejiang Province, College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou 310014, P. R. China
| | - Zhiqiang Liu
- The National and Local Joint Engineering Research Center for Biomanufacturing of Chiral Chemicals, Zhejiang University of Technology, Hangzhou 310014, P. R. China.,Key Laboratory of Bioorganic Synthesis of Zhejiang Province, College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou 310014, P. R. China
| | - Yuguo Zheng
- The National and Local Joint Engineering Research Center for Biomanufacturing of Chiral Chemicals, Zhejiang University of Technology, Hangzhou 310014, P. R. China.,Key Laboratory of Bioorganic Synthesis of Zhejiang Province, College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou 310014, P. R. China
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14
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Pu W, Chen J, Zhou Y, Qiu H, Shi T, Zhou W, Guo X, Cai N, Tan Z, Liu J, Feng J, Wang Y, Zheng P, Sun J. Systems metabolic engineering of Escherichia coli for hyper-production of 5‑aminolevulinic acid. BIOTECHNOLOGY FOR BIOFUELS AND BIOPRODUCTS 2023; 16:31. [PMID: 36829220 PMCID: PMC9951541 DOI: 10.1186/s13068-023-02280-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/13/2022] [Accepted: 02/09/2023] [Indexed: 02/26/2023]
Abstract
BACKGROUND 5-Aminolevulinic acid (5-ALA) is a promising biostimulant, feed nutrient, and photodynamic drug with wide applications in modern agriculture and therapy. Although microbial production of 5-ALA has been improved realized by using metabolic engineering strategies during the past few years, there is still a gap between the present production level and the requirement of industrialization. RESULTS In this study, pathway, protein, and cellular engineering strategies were systematically employed to construct an industrially competitive 5-ALA producing Escherichia coli. Pathways involved in precursor supply and product degradation were regulated by gene overexpression and synthetic sRNA-based repression to channel metabolic flux to 5-ALA biosynthesis. 5-ALA synthase was rationally engineered to release the inhibition of heme and improve the catalytic activity. 5-ALA transport and antioxidant defense systems were targeted to enhance cellular tolerance to intra- and extra-cellular 5-ALA. The final engineered strain produced 30.7 g/L of 5-ALA in bioreactors with a productivity of 1.02 g/L/h and a yield of 0.532 mol/mol glucose, represent a new record of 5-ALA bioproduction. CONCLUSIONS An industrially competitive 5-ALA producing E. coli strain was constructed with the metabolic engineering strategies at multiple layers (protein, pathway, and cellular engineering), and the strategies here can be useful for developing industrial-strength strains for biomanufacturing.
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Affiliation(s)
- Wei Pu
- Key Laboratory of Systems Microbial Biotechnology, Chinese Academy of Sciences, Tianjin Institute of Industrial Biotechnology, Tianjin, 300308 China
- National Technology Innovation Center of Synthetic Biology, Tianjin, 300308 China
| | - Jiuzhou Chen
- Key Laboratory of Systems Microbial Biotechnology, Chinese Academy of Sciences, Tianjin Institute of Industrial Biotechnology, Tianjin, 300308 China
- National Technology Innovation Center of Synthetic Biology, Tianjin, 300308 China
| | - Yingyu Zhou
- Key Laboratory of Systems Microbial Biotechnology, Chinese Academy of Sciences, Tianjin Institute of Industrial Biotechnology, Tianjin, 300308 China
- College of Biotechnology, Tianjin University of Science and Technology, Tianjin, 300457 China
| | - Huamin Qiu
- Key Laboratory of Systems Microbial Biotechnology, Chinese Academy of Sciences, Tianjin Institute of Industrial Biotechnology, Tianjin, 300308 China
- University of Chinese Academy of Sciences, Beijing, 100049 China
| | - Tuo Shi
- Key Laboratory of Systems Microbial Biotechnology, Chinese Academy of Sciences, Tianjin Institute of Industrial Biotechnology, Tianjin, 300308 China
- National Technology Innovation Center of Synthetic Biology, Tianjin, 300308 China
| | - Wenjuan Zhou
- Key Laboratory of Systems Microbial Biotechnology, Chinese Academy of Sciences, Tianjin Institute of Industrial Biotechnology, Tianjin, 300308 China
- National Technology Innovation Center of Synthetic Biology, Tianjin, 300308 China
| | - Xuan Guo
- Key Laboratory of Systems Microbial Biotechnology, Chinese Academy of Sciences, Tianjin Institute of Industrial Biotechnology, Tianjin, 300308 China
- National Technology Innovation Center of Synthetic Biology, Tianjin, 300308 China
| | - Ningyun Cai
- Key Laboratory of Systems Microbial Biotechnology, Chinese Academy of Sciences, Tianjin Institute of Industrial Biotechnology, Tianjin, 300308 China
- College of Biotechnology, Tianjin University of Science and Technology, Tianjin, 300457 China
| | - Zijian Tan
- Key Laboratory of Systems Microbial Biotechnology, Chinese Academy of Sciences, Tianjin Institute of Industrial Biotechnology, Tianjin, 300308 China
- National Technology Innovation Center of Synthetic Biology, Tianjin, 300308 China
| | - Jiao Liu
- Key Laboratory of Systems Microbial Biotechnology, Chinese Academy of Sciences, Tianjin Institute of Industrial Biotechnology, Tianjin, 300308 China
- National Technology Innovation Center of Synthetic Biology, Tianjin, 300308 China
| | - Jinhui Feng
- Key Laboratory of Systems Microbial Biotechnology, Chinese Academy of Sciences, Tianjin Institute of Industrial Biotechnology, Tianjin, 300308 China
- National Technology Innovation Center of Synthetic Biology, Tianjin, 300308 China
| | - Yu Wang
- Key Laboratory of Systems Microbial Biotechnology, Chinese Academy of Sciences, Tianjin Institute of Industrial Biotechnology, Tianjin, 300308 China
- National Technology Innovation Center of Synthetic Biology, Tianjin, 300308 China
- University of Chinese Academy of Sciences, Beijing, 100049 China
| | - Ping Zheng
- Key Laboratory of Systems Microbial Biotechnology, Chinese Academy of Sciences, Tianjin Institute of Industrial Biotechnology, Tianjin, 300308 China
- National Technology Innovation Center of Synthetic Biology, Tianjin, 300308 China
- University of Chinese Academy of Sciences, Beijing, 100049 China
| | - Jibin Sun
- Key Laboratory of Systems Microbial Biotechnology, Chinese Academy of Sciences, Tianjin Institute of Industrial Biotechnology, Tianjin, 300308 China
- National Technology Innovation Center of Synthetic Biology, Tianjin, 300308 China
- University of Chinese Academy of Sciences, Beijing, 100049 China
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15
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Heieck K, Arnold ND, Brück TB. Metabolic stress constrains microbial L-cysteine production in Escherichia coli by accelerating transposition through mobile genetic elements. Microb Cell Fact 2023; 22:10. [PMID: 36642733 PMCID: PMC9841684 DOI: 10.1186/s12934-023-02021-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2022] [Accepted: 01/09/2023] [Indexed: 01/17/2023] Open
Abstract
BACKGROUND L-cysteine is an essential chemical building block in the pharmaceutical-, cosmetic-, food and agricultural sector. Conventionally, L-cysteine production relies on the conversion of keratinous biomass mediated by hydrochloric acid. Today, fermentative production based on recombinant E. coli, where L-cysteine production is streamlined and facilitated by synthetic plasmid constructs, is an alternative process at industrial scale. However, metabolic stress and the resulting production escape mechanisms in evolving populations are severely limiting factors during industrial biomanufacturing. We emulate high generation numbers typically reached in industrial fermentation processes with Escherichia coli harbouring L-cysteine production plasmid constructs. So far no genotypic and phenotypic alterations in early and late L-cysteine producing E. coli populations have been studied. RESULTS In a comparative experimental design, the E. coli K12 production strain W3110 and the reduced genome strain MDS42, almost free of insertion sequences, were used as hosts. Data indicates that W3110 populations acquire growth fitness at the expense of L-cysteine productivity within 60 generations, while production in MDS42 populations remains stable. For the first time, the negative impact of predominantly insertion sequence family 3 and 5 transposases on L-cysteine production is reported, by combining differential transcriptome analysis with NGS based deep plasmid sequencing. Furthermore, metabolic clustering of differentially expressed genes supports the hypothesis, that metabolic stress induces rapid propagation of plasmid rearrangements, leading to reduced L-cysteine yields in evolving populations over industrial fermentation time scales. CONCLUSION The results of this study implicate how selective deletion of insertion sequence families could be a new route for improving industrial L-cysteine or even general amino acid production using recombinant E. coli hosts. Instead of using minimal genome strains, a selective deletion of certain IS families could offer the benefits of adaptive laboratory evolution (ALE) while maintaining enhanced L-cysteine production stability.
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Affiliation(s)
- Kevin Heieck
- grid.6936.a0000000123222966Technische Universität München, Lichtenbergstraße 4, 85748 Garching, Germany
| | - Nathanael David Arnold
- grid.6936.a0000000123222966Technische Universität München, Lichtenbergstraße 4, 85748 Garching, Germany
| | - Thomas Bartholomäus Brück
- grid.6936.a0000000123222966Technische Universität München, Lichtenbergstraße 4, 85748 Garching, Germany
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16
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Pokhrel A, Dinh H, Li L, Hassan KA, Cain AK, Paulsen IT. Identification of a Novel LysR Family Transcriptional Regulator Controlling Acquisition of Sulfur Sources in Acinetobacter baumannii. Microb Physiol 2023; 33:27-35. [PMID: 36626888 DOI: 10.1159/000529038] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2022] [Accepted: 12/30/2022] [Indexed: 01/11/2023]
Abstract
l-cysteine biosynthesis from inorganic sulfur represents a major mechanism by which reduced sulfur is incorporated into organic compounds. Cysteine biosynthesis and regulation is well characterized in Escherichia coli. However, the regulation of sulfur metabolism in Acinetobacter baumannii is only partly understood, with the LysR-type regulator, GigC known to control some aspects of sulfur reduction. In this study, we have used transcriptomics and bioinformatic analyses to characterize a novel LysR-type transcriptional regulator encoded by ABUW_1016 (cbl), in a highly multidrug resistant and virulent isolate of A. baumannii. We have shown that Cbl is involved in controlling expression of the genes required for uptake and reduction of various sulfur sources in A. baumannii. Collectively, we have identified the global regulon of Cbl and proposed a model of cysteine biosynthesis and its regulation by Cbl and GigC in A. baumannii.
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Affiliation(s)
- Alaska Pokhrel
- School of Natural Sciences, Macquarie University, Sydney, New South Wales, Australia,
| | - Hue Dinh
- School of Natural Sciences, Macquarie University, Sydney, New South Wales, Australia
| | - Liping Li
- School of Natural Sciences, Macquarie University, Sydney, New South Wales, Australia
| | - Karl A Hassan
- School of Environmental and Life Sciences, University of Newcastle, Newcastle, New South Wales, Australia
| | - Amy K Cain
- School of Natural Sciences, Macquarie University, Sydney, New South Wales, Australia
- ARC Centre of Excellence in Synthetic Biology, Macquarie University, Sydney, New South Wales, Australia
| | - Ian T Paulsen
- School of Natural Sciences, Macquarie University, Sydney, New South Wales, Australia
- ARC Centre of Excellence in Synthetic Biology, Macquarie University, Sydney, New South Wales, Australia
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17
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Ye C, Yang Y, Chen X, Yang L, Hua X, Yang M, Zeng X, Qiao S. Metabolic engineering of Escherichia coli BW25113 for the production of 5-Aminolevulinic Acid based on CRISPR/Cas9 mediated gene knockout and metabolic pathway modification. J Biol Eng 2022; 16:26. [PMID: 36229878 PMCID: PMC9563957 DOI: 10.1186/s13036-022-00307-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2022] [Accepted: 10/03/2022] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND 5-Aminolevulinic acid (ALA) recently received much attention due to its potential application in many fields. In this study, an ALA production strain of Escherichia coli was constructed by rational metabolic engineering and stepwise improvement based on known regulatory and metabolic information and CRISPR/Cas9 mediated gene knockout. RESULTS A metabolic strategy to produce ALA directly from glucose in this recombinant E. coli via the C5 pathway was applied herein. The rational metabolic engineering by gene knockouts significantly improved ALA production from 662.3 to 1601.7 mg/L. In addition, we managed to synergistically produce ALA via the C4 pathway in recombinant strain. The expression of a modified hemA gene, encoding an ALA synthase from Rhodobacter sphaeroides, improved ALA production from 1601.7 to 2099.7 mg/L. After 24 h cultivation, a yield of 0.210 g ALA per g glucose was achieved by constructed E. coli D5:FYABD-RSA. CONCLUSION Our study revealed that an industrially competitive strain can be efficiently developed by metabolic engineering based on combined rational modification and optimization of gene expression.
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Affiliation(s)
- Changchuan Ye
- State Key Laboratory of Animal Nutrition, Ministry of Agriculture Feed Industry Centre, China Agricultural University, Beijing, 100193, China
- Beijing Key Laboratory of Bio-Feed Additives, Beijing, 100193, China
| | - Yuting Yang
- State Key Laboratory of Animal Nutrition, Ministry of Agriculture Feed Industry Centre, China Agricultural University, Beijing, 100193, China
- Beijing Key Laboratory of Bio-Feed Additives, Beijing, 100193, China
| | - Xi Chen
- State Key Laboratory for Agro-Biotechnology, and Ministry of Agriculture and Rural Affairs, Key Laboratory for Pest Monitoring and Green Management, Department of Plant Pathology, China Agricultural University, Beijing, 100193, China
| | - Lijie Yang
- State Key Laboratory of Animal Nutrition, Ministry of Agriculture Feed Industry Centre, China Agricultural University, Beijing, 100193, China
- Beijing Key Laboratory of Bio-Feed Additives, Beijing, 100193, China
| | - Xia Hua
- State Key Laboratory for Agro-Biotechnology, and Ministry of Agriculture and Rural Affairs, Key Laboratory for Pest Monitoring and Green Management, Department of Plant Pathology, China Agricultural University, Beijing, 100193, China
| | - Mengjie Yang
- National Feed Engineering Technology Research Centre, Beijing, 100193, China
| | - Xiangfang Zeng
- State Key Laboratory of Animal Nutrition, Ministry of Agriculture Feed Industry Centre, China Agricultural University, Beijing, 100193, China
- Beijing Key Laboratory of Bio-Feed Additives, Beijing, 100193, China
| | - Shiyan Qiao
- State Key Laboratory of Animal Nutrition, Ministry of Agriculture Feed Industry Centre, China Agricultural University, Beijing, 100193, China.
- Beijing Key Laboratory of Bio-Feed Additives, Beijing, 100193, China.
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18
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Usuda Y, Nishio Y, Nonaka G, Hara Y. Microbial Production Potential of Pantoea ananatis: From Amino Acids to Secondary Metabolites. Microorganisms 2022; 10:microorganisms10061133. [PMID: 35744651 PMCID: PMC9231021 DOI: 10.3390/microorganisms10061133] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2022] [Revised: 05/25/2022] [Accepted: 05/27/2022] [Indexed: 11/16/2022] Open
Abstract
Pantoea ananatis, a gram-negative bacterium belonging to the Erwiniaceae family, is a well-known phytopathogen isolated from many ecological niches and plant hosts. However, this bacterium also provides us with various beneficial characteristics, such as the growth promotion of their host plants and increased crop yield. Some isolated non-pathogenic strains are promising for the microbial production of useful substances. P. ananatis AJ13355 was isolated as an acidophilic bacterium and was used as an excellent host to produce L-glutamic acid under acidic conditions. The genome sequence of P. ananatis AJ13355 was determined, and specific genome-engineering technologies were developed. As a result, P. ananatis was successfully used to construct a bacterial strain that produces cysteine, a sulfur-containing amino acid that has been difficult to produce through fermentation because of complex regulation. Furthermore, by heterologous expression including plant-derived genes, construction of a strain that produces isoprenoids such as isoprene and linalool as secondary metabolites was achieved. P. ananatis is shown to be a useful host for the production of secondary metabolites, as well as amino acids, and is expected to be used as a platform for microbial production of bioactive substances, aromatic substances, and other high-value-added substances of plant origin in the future.
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Affiliation(s)
- Yoshihiro Usuda
- Research and Business Planning Department, Ajinomoto Co., Inc., Tokyo 104-8315, Japan
- Correspondence: ; Tel.: +81-70-4361-3762; Fax: +81-3-5250-8352
| | - Yousuke Nishio
- Research Institute for Bioscience Products & Fine Chemicals, Ajinomoto Co., Inc., Kawasaki 210-8681, Japan; (Y.N.); (Y.H.)
| | - Gen Nonaka
- Ajinomoto-Genetika Research Institute, Moscow 117545, Russia;
| | - Yoshihiko Hara
- Research Institute for Bioscience Products & Fine Chemicals, Ajinomoto Co., Inc., Kawasaki 210-8681, Japan; (Y.N.); (Y.H.)
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19
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Malla S, van der Helm E, Darbani B, Wieschalka S, Förster J, Borodina I, Sommer MOA. A Novel Efficient L-Lysine Exporter Identified by Functional Metagenomics. Front Microbiol 2022; 13:855736. [PMID: 35495724 PMCID: PMC9048822 DOI: 10.3389/fmicb.2022.855736] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2022] [Accepted: 03/23/2022] [Indexed: 12/14/2022] Open
Abstract
Lack of active export system often limits the industrial bio-based production processes accumulating the intracellular product and hence complexing the purification steps. L-lysine, an essential amino acid, is produced biologically in quantities exceeding two million tons per year; yet, L-lysine production is challenged by efficient export system at high titers during fermentation. To address this issue, new exporter candidates for efficient efflux of L-lysine are needed. Using metagenomic functional selection, we identified 58 genes encoded on 28 unique metagenomic fragments from cow gut microbiome library that improved L-lysine tolerance. These genes include a novel L-lysine transporter, belonging to a previously uncharacterized EamA superfamily, which is further in vivo characterized as L-lysine exporter using Xenopus oocyte expression system as well as Escherichia coli host. This novel exporter improved L-lysine tolerance in E. coli by 40% and enhanced yield, titer, and the specific production of L-lysine in an industrial Corynebacterium glutamicum strain by 7.8%, 9.5%, and 12%, respectively. Our approach allows the sequence-independent discovery of novel exporters and can be deployed to increase titers and productivity of toxicity-limited bioprocesses.
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20
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Tian Y, Chen H, Chen L, Deng X, Hu Z, Wang C, Wei C, Qiu G, Wuertz S. Glycine adversely affects enhanced biological phosphorus removal. WATER RESEARCH 2022; 209:117894. [PMID: 34890912 DOI: 10.1016/j.watres.2021.117894] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/06/2021] [Revised: 11/04/2021] [Accepted: 11/21/2021] [Indexed: 06/13/2023]
Abstract
Enhanced biological phosphorus removal (EBPR) is used extensively in full-scale wastewater treatment plants for the removal of phosphorus. Despite previous evidence showing that glycine is a carbon source for a certain lineage of polyphosphate accumulating organisms (PAOs) such as Tetrasphaera, it is still unknown whether glycine can support EBPR. We observed an overall adverse effect of glycine on EBPR using activated sludge from both full-scale wastewater treatment plants and lab-scale reactors harboring distant and diverse PAOs and glycogen accumulating organisms (GAOs), including Candidatus Accumulibacter, Thiothrix, Tetrasphaera, Dechloromonas, Ca. Competibacter, and Defluviicoccus, among others. Glycine induced phosphorus (P) release under anaerobic conditions without being effectively taken up by cells. The induced P release rate correlated with glycine concentration in the range of 10 to 50 mg C/L. PAOs continued to release P in the presence of glycine under aerobic conditions without any evident P uptake. Under mixed carbon conditions, the occurrence of glycine did not seem to affect acetate uptake; however, it significantly reduced the rate of P uptake in the aerobic phase. Overall, glycine did not appear to be an effective carbon source for a majority of PAOs and GAOs in full-scale and lab-scale systems, and neither did other community members utilize glycine under anaerobic or aerobic conditions. Metatranscriptomic analysis showed the transcription of glycine cleavage T, P and H protein genes, but not of the L protein or the downstream genes in the glycine cleavage pathway, suggesting barriers to metabolizing glycine. The high transcription of a gene encoding a drug/metabolite transporter suggests a potential efflux mechanism, where glycine transported into the cells is in turn exported at the expense of ATP, resulting in P release without affecting the glycine concentration in solution. The ability of glycine to induce P release without cellular uptake suggests a way to effectively recover P from P-enriched waste sludge.
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Affiliation(s)
- Yucheng Tian
- School of Environment and Energy, South China University of Technology, Guangzhou 510006, China
| | - Hang Chen
- School of Environment and Energy, South China University of Technology, Guangzhou 510006, China
| | - Liping Chen
- School of Environment and Energy, South China University of Technology, Guangzhou 510006, China
| | - Xuhan Deng
- School of Environment and Energy, South China University of Technology, Guangzhou 510006, China
| | - Zekun Hu
- School of Environment and Energy, South China University of Technology, Guangzhou 510006, China
| | - Cenchao Wang
- School of Environment and Energy, South China University of Technology, Guangzhou 510006, China
| | - Chaohai Wei
- School of Environment and Energy, South China University of Technology, Guangzhou 510006, China; Key Laboratory of Pollution Control and Ecological Restoration in Industrial Clusters, Ministry of Education, Guangzhou 510006, China
| | - Guanglei Qiu
- School of Environment and Energy, South China University of Technology, Guangzhou 510006, China; Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, Singapore 637551, Singapore; Key Laboratory of Pollution Control and Ecological Restoration in Industrial Clusters, Ministry of Education, Guangzhou 510006, China.
| | - Stefan Wuertz
- Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, Singapore 637551, Singapore; School of Civil and Environmental Engineering, Nanyang Technological University, Singapore 639798, Singapore.
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21
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Functional Characterization of Transporters for L-Aspartate in Bacillus licheniformis. FERMENTATION 2022. [DOI: 10.3390/fermentation8010022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Amino acid efflux and influx transport systems play vital roles in industrial microorganisms’ cell growth and metabolism. However, although biochemically characterized, most of them remain unknown at the molecular level in Bacillus licheniformis. In this study, three proteins, namely, YdgF, YvbW, and YveA, were predicted to be involved in the active transport of L-aspartate (L-Asp). This was verified by manipulating their encoding genes. When growing in the minimal medium with L-Asp as the only carbon and nitrogen source, the growth of strains lacking proteins YdgF, YvbW, and YveA was significantly inhibited compared with the wild-type strains, while supplementing the expression of the corresponding proteins in the single-gene knockout strains could alleviate the inhibition. Upon overexpression, the recombinant proteins mediated the accumulation of L-aspartate to varying degrees. Compared with the wild-type strains, the single knockout strains of the three protein genes exhibited reduced absorption of L-aspartate. In addition, this study focused on the effects of these three proteins on the absorption of β-alanine, L-glutamate, D-serine, D-alanine, and glycine.
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22
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Shahbazi M, Tohidfar M, Azimzadeh Irani M, Moheb Seraj RG. Functional annotation and evaluation of hypothetical proteins in cyanobacterium Synechocystis sp. PCC 6803. BIOCATALYSIS AND AGRICULTURAL BIOTECHNOLOGY 2022. [DOI: 10.1016/j.bcab.2021.102246] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
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23
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Imura M, Etoh S, Iwakiri R, Okano K, Honda K. Improvement of production yield of l-cysteine through in vitro metabolic pathway with thermophilic enzymes. J Biosci Bioeng 2021; 132:585-591. [PMID: 34600806 DOI: 10.1016/j.jbiosc.2021.09.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2021] [Revised: 09/01/2021] [Accepted: 09/02/2021] [Indexed: 01/10/2023]
Abstract
The demand for the amino acid l-cysteine is increasing in the food, cosmetic, and pharmaceutical industries. Conventionally, the commercial production of l-cysteine is achieved by its extraction from the acid hydrolysate of hair and feathers. However, this production method is associated with the release of environmentally hazardous wastewater. Additionally, l-cysteine produced from animal sources cannot be halal-certified, which limits the market size. Although recent studies have developed an alternative commercial l-cysteine production method based on microbial fermentation, the production yield was insufficient owing to the cytotoxicity of l-cysteine against the host cells. In a previous study, we had developed an in vitrol-cysteine production method with a combination of 11 thermophilic enzymes, which yielded 10.5 mM l-cysteine from 20 mM glucose. In this study, we performed re-screening for enzymes catalyzing the rate-limiting steps of the in vitro pathway. Subsequently, the genes encoding enzymes necessary for the in vitro synthesis of l-cysteine were assembled in an expression vector and co-expressed in a single strain. To prevent the synthesis of hydrogen peroxide (H2O2), which is a byproduct and inhibits the enzyme activity, the redox balance in this biosynthetic pathway was maintained by replacing the H2O2-forming NADH oxidase with another enzymatic reaction in which pyruvate was used as a sacrificial substrate. The re-designed in vitro synthetic pathway resulted in the production of 28.2 mM l-cysteine from 20 mM glucose with a molar yield of 70.5%.
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Affiliation(s)
- Makoto Imura
- Mitsubishi Corporation Life Sciences Limited, 1-6 Higashihama, Saiki, Oita 876-8580, Japan
| | - Shinichi Etoh
- Mitsubishi Corporation Life Sciences Limited, 1-6 Higashihama, Saiki, Oita 876-8580, Japan
| | - Ryo Iwakiri
- Mitsubishi Corporation Life Sciences Limited, 1-6 Higashihama, Saiki, Oita 876-8580, Japan
| | - Kenji Okano
- International Center for Biotechnology, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan; Industrial Biotechnology Initiative Division, Institute for Open and Transdisciplinary Research Initiatives, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Kohsuke Honda
- International Center for Biotechnology, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan; Industrial Biotechnology Initiative Division, Institute for Open and Transdisciplinary Research Initiatives, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan.
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24
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Popella L, Jung J, Popova K, Ðurica-Mitić S, Barquist L, Vogel J. Global RNA profiles show target selectivity and physiological effects of peptide-delivered antisense antibiotics. Nucleic Acids Res 2021; 49:4705-4724. [PMID: 33849070 PMCID: PMC8096218 DOI: 10.1093/nar/gkab242] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Revised: 03/18/2021] [Accepted: 03/24/2021] [Indexed: 12/13/2022] Open
Abstract
Antisense peptide nucleic acids (PNAs) inhibiting mRNAs of essential genes provide a straight-forward way to repurpose our knowledge of bacterial regulatory RNAs for development of programmable species-specific antibiotics. While there is ample proof of PNA efficacy, their target selectivity and impact on bacterial physiology are poorly understood. Moreover, while antibacterial PNAs are typically designed to block mRNA translation, effects on target mRNA levels are not well-investigated. Here, we pioneer the use of global RNA-seq analysis to decipher PNA activity in a transcriptome-wide manner. We find that PNA-based antisense oligomer conjugates robustly decrease mRNA levels of the widely-used target gene, acpP, in Salmonella enterica, with limited off-target effects. Systematic analysis of several different PNA-carrier peptides attached not only shows different bactericidal efficiency, but also activation of stress pathways. In particular, KFF-, RXR- and Tat-PNA conjugates especially induce the PhoP/Q response, whereas the latter two additionally trigger several distinct pathways. We show that constitutive activation of the PhoP/Q response can lead to Tat-PNA resistance, illustrating the utility of RNA-seq for understanding PNA antibacterial activity. In sum, our study establishes an experimental framework for the design and assessment of PNA antimicrobials in the long-term quest to use these for precision editing of microbiota.
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Affiliation(s)
- Linda Popella
- Institute of Molecular Infection Biology (IMIB), University of Würzburg, D-97080 Würzburg, Germany
| | - Jakob Jung
- Institute of Molecular Infection Biology (IMIB), University of Würzburg, D-97080 Würzburg, Germany
| | - Kristina Popova
- Institute of Molecular Infection Biology (IMIB), University of Würzburg, D-97080 Würzburg, Germany
| | - Svetlana Ðurica-Mitić
- Institute of Molecular Infection Biology (IMIB), University of Würzburg, D-97080 Würzburg, Germany
| | - Lars Barquist
- Helmholtz Institute for RNA-based Infection Research (HIRI), Helmholtz Centre for Infection Research (HZI), D-97080 Würzburg, Germany.,Faculty of Medicine, University of Würzburg, D-97080 Würzburg, Germany
| | - Jörg Vogel
- Institute of Molecular Infection Biology (IMIB), University of Würzburg, D-97080 Würzburg, Germany.,Helmholtz Institute for RNA-based Infection Research (HIRI), Helmholtz Centre for Infection Research (HZI), D-97080 Würzburg, Germany.,Faculty of Medicine, University of Würzburg, D-97080 Würzburg, Germany
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25
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Khan MZ, Singha B, Ali MF, Taunk K, Rapole S, Gourinath S, Nandicoori VK. Redox homeostasis in Mycobacterium tuberculosis is modulated by a novel actinomycete-specific transcription factor. EMBO J 2021; 40:e106111. [PMID: 34018220 PMCID: PMC8280819 DOI: 10.15252/embj.2020106111] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Revised: 04/17/2021] [Accepted: 04/20/2021] [Indexed: 11/09/2022] Open
Abstract
Mycobacterium tuberculosis (Mtb) has evolved diverse cellular processes in response to the multiple stresses it encounters within the infected host. We explored available TnSeq datasets to identify transcription factors (TFs) that are essential for Mtb survival inside the host. The analysis identified a single TF, Rv1332 (AosR), conserved across actinomycetes with a so‐far uncharacterized function. AosR mitigates phagocyte‐derived oxidative and nitrosative stress, thus promoting mycobacterial growth in the murine lungs and spleen. Oxidative stress induces formation of a single intrasubunit disulphide bond in AosR, which in turn facilitates AosR interaction with an extracytoplasmic‐function sigma factor, SigH. This leads to the specific upregulation of the CysM‐dependent non‐canonical cysteine biosynthesis pathway through an auxiliary intragenic stress‐responsive promoter, an axis critical in detoxifying host‐derived oxidative and nitrosative radicals. Failure to upregulate AosR‐dependent cysteine biosynthesis during the redox stress causes differential expression of 6% of Mtb genes. Our study shows that the AosR‐SigH pathway is critical for detoxifying host‐derived oxidative and nitrosative radicals to enhance Mtb survival in the hostile intracellular environment.
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26
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Watanabe M, Chiba Y, Hirai MY. Metabolism and Regulatory Functions of O-Acetylserine, S-Adenosylmethionine, Homocysteine, and Serine in Plant Development and Environmental Responses. FRONTIERS IN PLANT SCIENCE 2021; 12:643403. [PMID: 34025692 PMCID: PMC8137854 DOI: 10.3389/fpls.2021.643403] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Accepted: 03/17/2021] [Indexed: 05/19/2023]
Abstract
The metabolism of an organism is closely related to both its internal and external environments. Metabolites can act as signal molecules that regulate the functions of genes and proteins, reflecting the status of these environments. This review discusses the metabolism and regulatory functions of O-acetylserine (OAS), S-adenosylmethionine (AdoMet), homocysteine (Hcy), and serine (Ser), which are key metabolites related to sulfur (S)-containing amino acids in plant metabolic networks, in comparison to microbial and animal metabolism. Plants are photosynthetic auxotrophs that have evolved a specific metabolic network different from those in other living organisms. Although amino acids are the building blocks of proteins and common metabolites in all living organisms, their metabolism and regulation in plants have specific features that differ from those in animals and bacteria. In plants, cysteine (Cys), an S-containing amino acid, is synthesized from sulfide and OAS derived from Ser. Methionine (Met), another S-containing amino acid, is also closely related to Ser metabolism because of its thiomethyl moiety. Its S atom is derived from Cys and its methyl group from folates, which are involved in one-carbon metabolism with Ser. One-carbon metabolism is also involved in the biosynthesis of AdoMet, which serves as a methyl donor in the methylation reactions of various biomolecules. Ser is synthesized in three pathways: the phosphorylated pathway found in all organisms and the glycolate and the glycerate pathways, which are specific to plants. Ser metabolism is not only important in Ser supply but also involved in many other functions. Among the metabolites in this network, OAS is known to function as a signal molecule to regulate the expression of OAS gene clusters in response to environmental factors. AdoMet regulates amino acid metabolism at enzymatic and translational levels and regulates gene expression as methyl donor in the DNA and histone methylation or after conversion into bioactive molecules such as polyamine and ethylene. Hcy is involved in Met-AdoMet metabolism and can regulate Ser biosynthesis at an enzymatic level. Ser metabolism is involved in development and stress responses. This review aims to summarize the metabolism and regulatory functions of OAS, AdoMet, Hcy, and Ser and compare the available knowledge for plants with that for animals and bacteria and propose a future perspective on plant research.
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Affiliation(s)
- Mutsumi Watanabe
- Graduate School of Biological Science, Nara Institute of Science and Technology, Ikoma, Japan
| | - Yukako Chiba
- Graduate School of Life Sciences, Faculty of Science, Hokkaido University, Sapporo, Japan
| | - Masami Yokota Hirai
- RIKEN Center for Sustainable Resource Science, Yokohama, Japan
- Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, Japan
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27
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Ahmed MS, Lauersen KJ, Ikram S, Li C. Efflux Transporters' Engineering and Their Application in Microbial Production of Heterologous Metabolites. ACS Synth Biol 2021; 10:646-669. [PMID: 33751883 DOI: 10.1021/acssynbio.0c00507] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Metabolic engineering of microbial hosts for the production of heterologous metabolites and biochemicals is an enabling technology to generate meaningful quantities of desired products that may be otherwise difficult to produce by traditional means. Heterologous metabolite production can be restricted by the accumulation of toxic products within the cell. Efflux transport proteins (transporters) provide a potential solution to facilitate the export of these products, mitigate toxic effects, and enhance production. Recent investigations using knockout lines, heterologous expression, and expression profiling of transporters have revealed candidates that can enhance the export of heterologous metabolites from microbial cell systems. Transporter engineering efforts have revealed that some exhibit flexible substrate specificity and may have broader application potentials. In this Review, the major superfamilies of efflux transporters, their mechanistic modes of action, selection of appropriate efflux transporters for desired compounds, and potential transporter engineering strategies are described for potential applications in enhancing engineered microbial metabolite production. Future studies in substrate recognition, heterologous expression, and combinatorial engineering of efflux transporters will assist efforts to enhance heterologous metabolite production in microbial hosts.
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Affiliation(s)
- Muhammad Saad Ahmed
- Institute for Synthetic Biosystem/Department of Biochemical Engineering, School of Chemistry and Chemical Engineering, Beijing Institute of Technology (BIT), Beijing 100081, P. R. China
- Department of Biological Sciences, National University of Medical Sciences (NUMS), Abid Majeed Road, The Mall, Rawalpindi 46000, Pakistan
| | - Kyle J. Lauersen
- Biological and Environmental Sciences and Engineering Division (BESE), King Abdullah University of Science and Technology (KAUST), Thuwal 23955, Kingdom of Saudi Arabia
| | - Sana Ikram
- Beijing Higher Institution Engineering Research Center for Food Additives and Ingredients, Beijing Technology & Business University (BTBU), Beijing 100048, P. R. China
| | - Chun Li
- Institute for Synthetic Biosystem/Department of Biochemical Engineering, School of Chemistry and Chemical Engineering, Beijing Institute of Technology (BIT), Beijing 100081, P. R. China
- SynBio Research Platform, Collaborative Innovation Center of Chemical Science and Engineering, Key Laboratory of Systems Bioengineering, Ministry of Education, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300350, P. R. China
- Key Laboratory for Industrial Biocatalysis, Ministry of Education, Department of Chemical Engineering, Tsinghua University, Beijing 100084, P. R. China
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28
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Henderson PJF, Maher C, Elbourne LDH, Eijkelkamp BA, Paulsen IT, Hassan KA. Physiological Functions of Bacterial "Multidrug" Efflux Pumps. Chem Rev 2021; 121:5417-5478. [PMID: 33761243 DOI: 10.1021/acs.chemrev.0c01226] [Citation(s) in RCA: 66] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Bacterial multidrug efflux pumps have come to prominence in human and veterinary pathogenesis because they help bacteria protect themselves against the antimicrobials used to overcome their infections. However, it is increasingly realized that many, probably most, such pumps have physiological roles that are distinct from protection of bacteria against antimicrobials administered by humans. Here we undertake a broad survey of the proteins involved, allied to detailed examples of their evolution, energetics, structures, chemical recognition, and molecular mechanisms, together with the experimental strategies that enable rapid and economical progress in understanding their true physiological roles. Once these roles are established, the knowledge can be harnessed to design more effective drugs, improve existing microbial production of drugs for clinical practice and of feedstocks for commercial exploitation, and even develop more sustainable biological processes that avoid, for example, utilization of petroleum.
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Affiliation(s)
- Peter J F Henderson
- School of Biomedical Sciences and Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds LS2 9JT, United Kingdom
| | - Claire Maher
- School of Environmental and Life Sciences, University of Newcastle, Callaghan 2308, New South Wales, Australia
| | - Liam D H Elbourne
- Department of Biomolecular Sciences, Macquarie University, Sydney 2109, New South Wales, Australia.,ARC Centre of Excellence in Synthetic Biology, Macquarie University, Sydney 2019, New South Wales, Australia
| | - Bart A Eijkelkamp
- College of Science and Engineering, Flinders University, Bedford Park 5042, South Australia, Australia
| | - Ian T Paulsen
- Department of Biomolecular Sciences, Macquarie University, Sydney 2109, New South Wales, Australia.,ARC Centre of Excellence in Synthetic Biology, Macquarie University, Sydney 2019, New South Wales, Australia
| | - Karl A Hassan
- School of Environmental and Life Sciences, University of Newcastle, Callaghan 2308, New South Wales, Australia.,ARC Centre of Excellence in Synthetic Biology, Macquarie University, Sydney 2019, New South Wales, Australia
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29
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Morigasaki S, Umeyama A, Kawano Y, Aizawa Y, Ohtsu I. Defect of RNA pyrophosphohydrolase RppH enhances fermentative production of L-cysteine in Escherichia coli. J GEN APPL MICROBIOL 2021; 66:307-314. [PMID: 32779574 DOI: 10.2323/jgam.2019.12.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Fermentative production of L-cysteine has been established using Escherichia coli. In that procedure, thiosulfate is a beneficial sulfur source, whereas repressing sulfate utilization. We first found that thiosulfate decreased transcript levels of genes related to sulfur assimilation, particularly whose expression is controlled by the transcription factor CysB. Therefore, a novel approach, i.e. increment of expression of genes involved in sulfur-assimilation, was attempted for further improvement of L-cysteine overproduction. Disruption of the rppH gene significantly augmented transcript levels of the cysD, cysJ, cysM and yeeE genes (≥1.5-times) in medium containing sulfate as a sole sulfur source, probably because the rppH gene encodes mRNA pyrophosphohydrolase that triggers degradation of certain mRNAs. In addition, the ΔrppH strain appeared to preferentially uptake thiosulfate rather than sulfate, though thiosulfate dramatically reduced expression of the known sulfate/thiosulfate transporter complexes in both ΔrppH and wild-type cells. We also found that both YeeE and YeeD are required for the strain without the transporters to grow in the presence of thiosulfate as a sole sulfur source. Therefore, yeeE and yeeD are assigned as genes responsible for thiosulfate uptake (tsuA and tsuB, respectively). In final, we applied the ΔrppH strain to the fermentative production of L-cysteine. Disruption of the rppH gene enhanced L-cysteine biosynthesis, as a result, a strain producing approximately twice as much L-cysteine as the control strain was obtained.
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Affiliation(s)
- Susumu Morigasaki
- Graduate School of Life and Environmental Sciences, University of Tsukuba
| | | | - Yusuke Kawano
- Graduate School of Life and Environmental Sciences, University of Tsukuba
| | | | - Iwao Ohtsu
- Graduate School of Life and Environmental Sciences, University of Tsukuba
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30
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Production and Excretion of Polyamines To Tolerate High Ammonia, a Case Study on Soil Ammonia-Oxidizing Archaeon " Candidatus Nitrosocosmicus agrestis". mSystems 2021; 6:6/1/e01003-20. [PMID: 33594004 PMCID: PMC8573960 DOI: 10.1128/msystems.01003-20] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Ammonia tolerance is a universal characteristic among the ammonia-oxidizing bacteria (AOB); in contrast, the known species of ammonia-oxidizing archaea (AOA) have been regarded as ammonia sensitive, until the identification of the genus “Candidatus Nitrosocosmicus.” However, the mechanism of its ammonia tolerance has not been reported. In this study, the AOA species “Candidatus Nitrosocosmicus agrestis,” obtained from agricultural soil, was determined to be able to tolerate high concentrations of NH3 (>1,500 μM). In the genome of this strain, which was recovered from metagenomic data, a full set of genes for the pathways of polysaccharide metabolism, urea hydrolysis, arginine synthesis, and polyamine synthesis was identified. Among them, the genes encoding cytoplasmic carbonic anhydrase (CA) and a potential polyamine transporter (drug/metabolite exporter [DME]) were found to be unique to the genus “Ca. Nitrosocosmicus.” When “Ca. Nitrosocosmicus agrestis” was grown with high levels of ammonia, the genes that participate in CO2/HCO3− conversion, glutamate/glutamine syntheses, arginine synthesis, polyamine synthesis, and polyamine excretion were significantly upregulated, and the polyamines, including putrescine and spermidine, had significant levels of production. Based on genome analysis, gene expression quantification, and polyamine determination, we propose that the production and excretion of polyamines is probably one of the reasons for the ammonia tolerance of “Ca. Nitrosocosmicus agrestis,” and even of the genus “Ca. Nitrosocosmicus.” IMPORTANCE Ammonia tolerance of AOA is usually much lower than that of the AOB, which makes the AOB rather than AOA a predominant ammonia oxidizer in agricultural soils, contributing to global N2O emission. Recently, some AOA species from the genus “Ca. Nitrosocosmicus” were also found to have high ammonia tolerance. However, the reported mechanism for the ammonia tolerance is very rare and indeterminate for AOB and for AOA species. In this study, an ammonia-tolerant AOA strain of the species “Ca. Nitrosocosmicus agrestis” was identified and its potential mechanisms for ammonia tolerance were explored. This study will be of benefit for determining more of the ecological role of AOA in agricultural soils or other environments.
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31
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Liu H, Wang Y, Hou Y, Li Z. Fitness of Chassis Cells and Metabolic Pathways for l-Cysteine Overproduction in Escherichia coli. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2020; 68:14928-14937. [PMID: 33264003 DOI: 10.1021/acs.jafc.0c06134] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
l-Cysteine is a ubiquitous and unique sulfur-containing amino acid with numerous applications in agricultural and food industries. The efficient production of l-cysteine via microbial fermentation has received a great deal of attention. In this study, the fitness of different Escherichia coli K-12 strains harboring plasmid pLH03 was investigated. The enhancement of the precursor synthetic pathway and thiosulfate assimilation pathway resulted in the good performance of the E. coli BW25113 strain. The expression levels of synthetic pathway genes were optimized by two constitutive promoters to assess their effects on cysteine production. In conjunction, the main degradation pathway genes were also deleted for more efficient production of cysteine. l-Cysteine production was further increased through the manipulation of the sulfur transcription regulator cysB and sulfur supplementation. After process optimization in a 1.5 L bioreactor, LH2A1M0BΔYTS-pLH03 [BW25113 Ptrc2-serA Ptrc1-cysMPtrc-cysBΔyhaMΔtnaAΔsdaA-(pLH03)] accumulated 8.34 g/L cysteine, laying a foundation for application in the cysteine fermentation industry.
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Affiliation(s)
- Han Liu
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai 200237, China
| | - Yu Wang
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai 200237, China
| | - Yehua Hou
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai 200237, China
| | - Zhimin Li
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai 200237, China
- Shanghai Collaborative Innovation Center for Biomanufacturing Technology, 130 Meilong Road, Shanghai 200237, China
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32
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Teelucksingh T, Thompson LK, Cox G. The Evolutionary Conservation of Escherichia coli Drug Efflux Pumps Supports Physiological Functions. J Bacteriol 2020; 202:e00367-20. [PMID: 32839176 PMCID: PMC7585057 DOI: 10.1128/jb.00367-20] [Citation(s) in RCA: 45] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Bacteria harness an impressive repertoire of resistance mechanisms to evade the inhibitory action of antibiotics. One such mechanism involves efflux pump-mediated extrusion of drugs from the bacterial cell, which significantly contributes to multidrug resistance. Intriguingly, most drug efflux pumps are chromosomally encoded components of the intrinsic antibiotic resistome. In addition, in terms of xenobiotic detoxification, bacterial efflux systems often exhibit significant levels of functional redundancy. Efflux pumps are also considered to be highly conserved; however, the extent of conservation in many bacterial species has not been reported and the majority of genes that encode efflux pumps appear to be dispensable for growth. These observations, in combination with an increasing body of experimental evidence, imply alternative roles in bacterial physiology. Indeed, the ability of efflux pumps to facilitate antibiotic resistance could be a fortuitous by-product of ancient physiological functions. Using Escherichia coli as a model organism, we here evaluated the evolutionary conservation of drug efflux pumps and we provide phylogenetic analysis of the major efflux families. We show the E. coli drug efflux system has remained relatively stable and the majority (∼80%) of pumps are encoded in the core genome. This analysis further supports the importance of drug efflux pumps in E. coli physiology. In this review, we also provide an update on the roles of drug efflux pumps in the detoxification of endogenously synthesized substrates and pH homeostasis. Overall, gaining insight into drug efflux pump conservation, common evolutionary ancestors, and physiological functions could enable strategies to combat these intrinsic and ancient elements.
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Affiliation(s)
- Tanisha Teelucksingh
- College of Biological Sciences, Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario, Canada
| | - Laura K Thompson
- College of Biological Sciences, Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario, Canada
| | - Georgina Cox
- College of Biological Sciences, Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario, Canada
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Buckley C, Beatson SA, Limnios A, Lahra MM, Whiley DM, Forde BM. Whole-genome sequencing as an improved means of investigating Neisseria gonorrhoeae treatment failures. Sex Health 2020; 16:500-507. [PMID: 31481151 DOI: 10.1071/sh19012] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2019] [Accepted: 08/22/2019] [Indexed: 11/23/2022]
Abstract
Background Although rare, Neisseria gonorrhoeae treatment failures associated with ceftriaxone have been reported. The World Health Organization (WHO) recommends standardised protocols to verify these cases. Two cases from Australia were previously investigated using N. gonorrhoeae multiantigen sequence typing (NG-MAST), which has been used extensively to assess treatment failures. Case 1 pharyngeal isolates were indistinguishable, whereas Case 2 pharyngeal isolates were distinguished based on an 18-bp deletion in the major outer membrane porin encoded by the porB gene, questioning the reliability of NG-MAST results. Here we used whole-genome sequencing (WGS) to reinvestigate Cases 1 and 2, with a view to examining WGS to assess treatment failures. METHODS Pre- and post-treatment isolates for each case underwent Illumina sequencing, and the two post-treatment isolates underwent additional long-read sequencing using Pacific Biosciences. Sequence data were interrogated to identify differences at single nucleotide resolution. RESULTS WGS identified variation in the pilin subunit encoded by the pilE locus for both cases and the specific 18-bp porB deletion in Case 2 was confirmed, but otherwise the isolates in each case were indistinguishable. CONCLUSIONS The WHO recommends standardised protocols for verifying N. gonorrhoeae treatment failures. Case 2 highlights the enhanced resolution of WGS over NG-MAST and emphasises the immediate effect that WGS can have in a direct clinical application for N. gonorrhoeae. Assessing the whole genome compared with two highly variable regions also provides a more confident predictor for determining treatment failure. Furthermore, WGS facilitates rapid comparisons of these cases in the future.
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Affiliation(s)
- Cameron Buckley
- Faculty of Medicine, UQ Centre for Clinical Research, The University of Queensland, Herston, Qld 4029, Australia
| | - Scott A Beatson
- Australian Infectious Diseases Research Centre, The University of Queensland, Brisbane, Qld 4072, Australia; and Australian Centre for Ecogenomics, The University of Queensland, Brisbane, Qld 4072, Australia; and School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Qld 4072, Australia
| | - Athena Limnios
- WHO Collaborating Centre for STI and AMR, Microbiology Department, New South Wales Health Pathology, Prince of Wales Hospital, Sydney, NSW 2031, Australia
| | - Monica M Lahra
- WHO Collaborating Centre for STI and AMR, Microbiology Department, New South Wales Health Pathology, Prince of Wales Hospital, Sydney, NSW 2031, Australia; and School of Medical Sciences, UNSW, Sydney, NSW 2052, Australia
| | - David M Whiley
- Faculty of Medicine, UQ Centre for Clinical Research, The University of Queensland, Herston, Qld 4029, Australia; and Australian Infectious Diseases Research Centre, The University of Queensland, Brisbane, Qld 4072, Australia; and Pathology Queensland, Microbiology Department, Herston, Qld 4029, Australia
| | - Brian M Forde
- Australian Infectious Diseases Research Centre, The University of Queensland, Brisbane, Qld 4072, Australia; and Australian Centre for Ecogenomics, The University of Queensland, Brisbane, Qld 4072, Australia; and School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Qld 4072, Australia; and Corresponding author:
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Protective Role of Bacterial Alkanesulfonate Monooxygenase under Oxidative Stress. Appl Environ Microbiol 2020; 86:AEM.00692-20. [PMID: 32503904 DOI: 10.1128/aem.00692-20] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2020] [Accepted: 05/26/2020] [Indexed: 01/05/2023] Open
Abstract
Bacterial alkane metabolism is associated with a number of cellular stresses, including membrane stress and oxidative stress, and the limited uptake of charged ions such as sulfate. In the present study, the genes ssuD and tauD in Acinetobacter oleivorans DR1 cells, which encode an alkanesulfonate monooxygenase and a taurine dioxygenase, respectively, were found to be responsible for hexadecanesulfonate (C16SO3H) and taurine metabolism, and Cbl was experimentally identified as a potential regulator of ssuD and tauD expression. The expression of ssuD and tauD occurred under sulfate-limited conditions generated during n-hexadecane degradation. Interestingly, expression analysis and knockout experiments suggested that both genes are required to protect cells against oxidative stress, including that generated by n-hexadecane degradation and H2O2 exposure. Measurable levels of intracellular hexadecanesulfonate were also produced during n-hexadecane degradation. Phylogenetic analysis suggested that ssuD and tauD are mainly present in soil-dwelling aerobes within the Betaproteobacteria and Gammaproteobacteria classes, which suggests that they function as controllers of the sulfur cycle and play a protective role against oxidative stress in sulfur-limited conditions.IMPORTANCE ssuD and tauD, which play a role in the degradation of organosulfonate, were expressed during n-hexadecane metabolism and oxidative stress conditions in A. oleivorans DR1. Our study confirmed that hexadecanesulfonate was accidentally generated during bacterial n-hexadecane degradation in sulfate-limited conditions. Removal of this by-product by SsuD and TauD must be necessary for bacterial survival under oxidative stress generated during n-hexadecane degradation.
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High-yield production of L-serine through a novel identified exporter combined with synthetic pathway in Corynebacterium glutamicum. Microb Cell Fact 2020; 19:115. [PMID: 32471433 PMCID: PMC7260847 DOI: 10.1186/s12934-020-01374-5] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2020] [Accepted: 05/25/2020] [Indexed: 01/08/2023] Open
Abstract
Background l-Serine has wide and increasing applications in industries with fast-growing market demand. Although strategies for achieving and improving l-serine production in Corynebacterium glutamicum (C. glutamicum) have focused on inhibiting its degradation and enhancing its biosynthetic pathway, l-serine yield has remained relatively low. Exporters play an essential role in the fermentative production of amino acids. To achieve higher l-serine yield, l-serine export from the cell should be improved. In C. glutamicum, ThrE, which can export l-threonine and l-serine, is the only identified l-serine exporter so far. Results In this study, a novel l-serine exporter NCgl0580 was identified and characterized in C. glutamicum ΔSSAAI (SSAAI), and named as SerE (encoded by serE). Deletion of serE in SSAAI led to a 56.5% decrease in l-serine titer, whereas overexpression of serE compensated for the lack of serE with respect to l-serine titer. A fusion protein with SerE and enhanced green fluorescent protein (EGFP) was constructed to confirm that SerE localized at the plasma membrane. The function of SerE was studied by peptide feeding approaches, and the results showed that SerE is a novel exporter for l-serine and l-threonine in C. glutamicum. Subsequently, the interaction of a known l-serine exporter ThrE and SerE was studied, and the results suggested that SerE is more important than ThrE in l-serine export in SSAAI. In addition, probe plasmid and electrophoretic mobility shift assays (EMSA) revealed NCgl0581 as the transcriptional regulator of SerE. Comparative transcriptomics between SSAAI and the NCgl0581 deletion strain showed that NCgl0581 is a positive regulator of NCgl0580. Finally, by overexpressing the novel exporter SerE, combined with l-serine synthetic pathway key enzyme serAΔ197, serC, and serB, the resulting strain presented an l-serine titer of 43.9 g/L with a yield of 0.44 g/g sucrose, which is the highest l-serine titer and yield reported so far in C. glutamicum. Conclusions This study provides a novel target for l-serine and l-threonine export engineering as well as a new global transcriptional regulator NCgl0581 in C. glutamicum.
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Onyeabor M, Martinez R, Kurgan G, Wang X. Engineering transport systems for microbial production. ADVANCES IN APPLIED MICROBIOLOGY 2020; 111:33-87. [PMID: 32446412 DOI: 10.1016/bs.aambs.2020.01.002] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
The rapid development in the field of metabolic engineering has enabled complex modifications of metabolic pathways to generate a diverse product portfolio. Manipulating substrate uptake and product export is an important research area in metabolic engineering. Optimization of transport systems has the potential to enhance microbial production of renewable fuels and chemicals. This chapter comprehensively reviews the transport systems critical for microbial production as well as current genetic engineering strategies to improve transport functions and thus production metrics. In addition, this chapter highlights recent advancements in engineering microbial efflux systems to enhance cellular tolerance to industrially relevant chemical stress. Lastly, future directions to address current technological gaps are discussed.
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Affiliation(s)
- Moses Onyeabor
- School of Life Sciences, Arizona State University, Tempe, AZ, United States
| | - Rodrigo Martinez
- School of Life Sciences, Arizona State University, Tempe, AZ, United States
| | - Gavin Kurgan
- School of Life Sciences, Arizona State University, Tempe, AZ, United States
| | - Xuan Wang
- School of Life Sciences, Arizona State University, Tempe, AZ, United States.
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Kishino M, Kondoh M, Hirasawa T. Enhanced L-cysteine production by overexpressing potential L-cysteine exporter genes in an L-cysteine-producing recombinant strain of Corynebacterium glutamicum. Biosci Biotechnol Biochem 2019; 83:2390-2393. [DOI: 10.1080/09168451.2019.1659715] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
ABSTRACT
We identified L-cysteine exporter candidates of Corynebacterium glutamicum and investigated the effect of overexpression of the potential L-cysteine exporter genes on L-cysteine production in a recombinant strain of C. glutamicum. Overexpression of NCgl2566 and NCgl0580 resulted in enhanced L-cysteine production in an L-cysteine-producing recombinant strain of C. glutamicum.
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Affiliation(s)
- Mayumi Kishino
- School of Life Science and Technology, Tokyo Institute of Technology, Yokohama, Japan
| | - Mariko Kondoh
- School of Life Science and Technology, Tokyo Institute of Technology, Yokohama, Japan
| | - Takashi Hirasawa
- School of Life Science and Technology, Tokyo Institute of Technology, Yokohama, Japan
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Smirnova GV, Tyulenev AV, Bezmaternykh KV, Muzyka NG, Ushakov VY, Oktyabrsky ON. Cysteine homeostasis under inhibition of protein synthesis in Escherichia coli cells. Amino Acids 2019; 51:1577-1592. [PMID: 31617110 DOI: 10.1007/s00726-019-02795-2] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2019] [Accepted: 10/02/2019] [Indexed: 01/23/2023]
Abstract
Increased intracellular cysteine poses a potential danger to cells due to the high ability of cysteine to reduce free iron and promote the Fenton reaction. Here, we studied ways to maintain cysteine homeostasis in E. coli cells while inhibiting protein synthesis with valine or chloramphenicol. When growing wild-type bacteria on minimal medium with sulfate, an excess of cysteine resulting from the inhibition of protein synthesis is mainly incorporated into glutathione (up to 90%), which, therefore, can be considered as cysteine buffer. The share of hydrogen sulfide, which is the product of cysteine degradation by cysteine synthase B (CysM), does not exceed 1-3%, the rest falls on free cysteine, exported from cells. As a result, intracellular free cysteine is maintained at a low level (about 0.1 mM). The lack of glutathione in the gshA mutant increases H2S production and excretion of cysteine and leads to a threefold increase in the level of intracellular cysteine in response to valine and chloramphenicol. The relA mutants, exposed to valine, produce more H2S, dramatically accelerate the export of glutathione and accumulate more cysteine in the cytoplasm than their parent, which indicates that the regulatory nucleotide (p)ppGpp is involved in maintaining cysteine homeostasis. Disruption of cysteine homeostasis in gshA and relA mutants increases their sensitivity to peroxide stress.
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Affiliation(s)
- Galina V Smirnova
- Institute of Ecology and Genetics of Microorganisms, Russian Academy of Sciences, Golev Street 13, 614081, Perm, Russia.
| | - Aleksey V Tyulenev
- Institute of Ecology and Genetics of Microorganisms, Russian Academy of Sciences, Golev Street 13, 614081, Perm, Russia
| | - Kseniya V Bezmaternykh
- Institute of Ecology and Genetics of Microorganisms, Russian Academy of Sciences, Golev Street 13, 614081, Perm, Russia
| | - Nadezda G Muzyka
- Institute of Ecology and Genetics of Microorganisms, Russian Academy of Sciences, Golev Street 13, 614081, Perm, Russia
| | - Vadim Y Ushakov
- Institute of Ecology and Genetics of Microorganisms, Russian Academy of Sciences, Golev Street 13, 614081, Perm, Russia.,Perm State University, Bukireva Street 15, 614990, Perm, Russia
| | - Oleg N Oktyabrsky
- Institute of Ecology and Genetics of Microorganisms, Russian Academy of Sciences, Golev Street 13, 614081, Perm, Russia.,Perm National Research Polytechnic University, Komsomolsky Pr. 29, 614990, Perm, Russia
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L-Alanine Exporter, AlaE, of Escherichia coli Functions as a Safety Valve to Enhance Survival under Feast Conditions. Int J Mol Sci 2019; 20:ijms20194942. [PMID: 31591285 PMCID: PMC6801825 DOI: 10.3390/ijms20194942] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2019] [Revised: 10/03/2019] [Accepted: 10/04/2019] [Indexed: 11/17/2022] Open
Abstract
The intracellular level of amino acids is determined by the balance between their anabolic and catabolic pathways. L-alanine is anabolized by three L-alanine synthesizing enzymes and catabolized by two racemases and D-amino acid dehydrogenase (DadA). In addition, its level is regulated by L-alanine movement across the inner membrane. We identified the novel gene alaE, encoding an L-alanine exporter. To elucidate the physiological function of L-Alanine exporter, AlaE, we determined the susceptibility of alaE-, dadA-, and alaE/dadA-deficient mutants, derived from the wild-type strain MG1655, to L-alanyl-L-alanine (Ala-Ala), which shows toxicity to the L-alanine-nonmetabolizing variant lacking alaE. The dadA-deficient mutant has a similar minimum inhibitory concentration (MIC) (>1.25 mg/mL) to that observed in MG1655. However, alaE- and alaE/dadA-deficient mutants had MICs of 0.04 and 0.0025 mg/mL, respectively. The results suggested that the efficacy of AlaE to relieve stress caused by toxic intracellular accumulation of L-alanine was higher than that of DadA. Consistent with this, the intracellular level of alanine in the alaE-mutant was much higher than that in MG1655 and the dadA-mutant. We, therefore, conclude that AlaE functions as a ‘safety-valve’ to prevent the toxic level accumulation of intracellular L-alanine under a peptide-rich environment, such as within the animal intestine.
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Hanatani Y, Imura M, Taniguchi H, Okano K, Toya Y, Iwakiri R, Honda K. In vitro production of cysteine from glucose. Appl Microbiol Biotechnol 2019; 103:8009-8019. [PMID: 31396682 DOI: 10.1007/s00253-019-10061-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2019] [Revised: 07/05/2019] [Accepted: 07/24/2019] [Indexed: 12/19/2022]
Abstract
Cysteine is a commercially valuable amino acid with an increasing demand in the food, cosmetic, and pharmaceutical industries. Although cysteine is conventionally manufactured by extraction from animal proteins, this method has several problems, such as troublesome waste-water treatment and incompatibility with some dietary restrictions. Fermentative production of cysteine from plant-derived substrates is a promising alternative for the industrial production of cysteine. However, it often suffers from low product yield as living organisms are equipped with various regulatory systems to control the intracellular cysteine concentration at a moderate level. In this study, we constructed an in vitro cysteine biosynthetic pathway by assembling 11 thermophilic enzymes. The in vitro pathway was designed to be insensitive to the feedback regulation by cysteine and to balance the intra-pathway consumption and regeneration of cofactors. A kinetic model for the in vitro pathway was built using rate equations of individual enzymes and used to optimize the loading ratio of each enzyme. Consequently, 10.5 mM cysteine could be produced from 20 mM glucose through the optimized pathway. However, the observed yield and production rate of the assay were considerably lower than those predicted by the model. Determination of cofactor concentrations in the reaction mixture indicated that the inconsistency between the model and experimental assay could be attributed to the depletion of ATP and ADP, likely due to host-derived, thermo-stable enzyme(s). Based on these observations, possible approaches to improve the feasibility of cysteine production through an in vitro pathway have been discussed.
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Affiliation(s)
- Yohei Hanatani
- Department of Biotechnology, Graduate School of Engineering, Osaka University, Yamadaoka 2-1, Suita, Osaka, 565-0871, Japan
| | - Makoto Imura
- Bio Science Research Center, Mitsubishi Corporation Life Sciences Ltd., Higashihama 1-6, Saiki, Oita, 876-8580, Japan
| | - Hironori Taniguchi
- Department of Biotechnology, Graduate School of Engineering, Osaka University, Yamadaoka 2-1, Suita, Osaka, 565-0871, Japan
| | - Kenji Okano
- Department of Biotechnology, Graduate School of Engineering, Osaka University, Yamadaoka 2-1, Suita, Osaka, 565-0871, Japan
| | - Yoshihiro Toya
- Department of Bioinformatic Engineering, Graduate School of Information Science and Technology, Osaka University, Yamadaoka 1-5, Suita, Osaka, 565-0871, Japan
| | - Ryo Iwakiri
- Bio Science Research Center, Mitsubishi Corporation Life Sciences Ltd., Higashihama 1-6, Saiki, Oita, 876-8580, Japan
| | - Kohsuke Honda
- Department of Biotechnology, Graduate School of Engineering, Osaka University, Yamadaoka 2-1, Suita, Osaka, 565-0871, Japan.
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Han P, Yu Y, Zhou L, Tian Z, Li Z, Hou L, Liu M, Wu Q, Wagner M, Men Y. Specific Micropollutant Biotransformation Pattern by the Comammox Bacterium Nitrospira inopinata. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2019; 53:8695-8705. [PMID: 31294971 DOI: 10.1021/acs.est.9b01037] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
The recently discovered complete ammonia-oxidizing (comammox) bacteria occur in various environments, including wastewater treatment plants. To better understand their role in micropollutant biotransformation in comparison with ammonia-oxidizing bacteria (AOB) and ammonia-oxidizing archaea (AOA), we investigated the biotransformation capability of Nitrospira inopinata (the only comammox isolate) for 17 micropollutants. Asulam, fenhexamid, mianserin, and ranitidine were biotransformed by N. inopinata, Nitrososphaera gargensis (AOA), and Nitrosomonas nitrosa Nm90 (AOB). More distinctively, carbendazim, a benzimidazole fungicide, was exclusively biotransformed by N. inopinata. The biotransformation of carbendazim only occurred when N. inopinata was supplied with ammonia but not nitrite as the energy source. The exclusive biotransformation of carbendazim by N. inopinata was likely enabled by an enhanced substrate promiscuity of its unique AMO and its much higher substrate (for ammonia) affinity compared with the other two ammonia oxidizers. One major plausible transformation product (TP) of carbendazim is a hydroxylated form at the aromatic ring, which is consistent with the function of AMO. These findings provide fundamental knowledge on the micropollutant degradation potential of a comammox bacterium to better understand the fate of micropollutants in nitrifying environments.
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Affiliation(s)
- Ping Han
- Centre for Microbiology and Environmental Systems Science, Division of Microbial Ecology , University of Vienna , Althanstrasse 14 , 1090 Vienna , Austria
| | - Yaochun Yu
- Department of Civil and Environmental Engineering , University of Illinois at Urbana-Champaign , Urbana , Illinois 61801 , United States
| | - Lijun Zhou
- Centre for Microbiology and Environmental Systems Science, Division of Microbial Ecology , University of Vienna , Althanstrasse 14 , 1090 Vienna , Austria
- State Key Laboratory of Lake Science and Environment , Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences , Nanjing 210008 , China
| | - Zhenyu Tian
- Center for Urban Waters , University of Washington Tacoma , Tacoma , Washington 98421 , United States
| | - Zhong Li
- Metabolomics Center , University of Illinois , Urbana , Illinois 61801 , United States
| | | | | | - Qinglong Wu
- State Key Laboratory of Lake Science and Environment , Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences , Nanjing 210008 , China
- Sino-Danish Center for Education and Science , University of Chinese Academy of Science , Beijing 100190 , China
| | - Michael Wagner
- Centre for Microbiology and Environmental Systems Science, Division of Microbial Ecology , University of Vienna , Althanstrasse 14 , 1090 Vienna , Austria
- The Comammox Research Platform of the University of Vienna , 1090 Vienna , Austria
- Department of Biotechnology, Chemistry and Bioscience , Aalborg University , 9100 Aalborg , Denmark
| | - Yujie Men
- Department of Civil and Environmental Engineering , University of Illinois at Urbana-Champaign , Urbana , Illinois 61801 , United States
- Institute for Genomic Biology , University of Illinois at Urbana-Champaign , Urbana , Illinois 61801 , United States
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Wendisch VF. Metabolic engineering advances and prospects for amino acid production. Metab Eng 2019; 58:17-34. [PMID: 30940506 DOI: 10.1016/j.ymben.2019.03.008] [Citation(s) in RCA: 147] [Impact Index Per Article: 29.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2019] [Revised: 03/26/2019] [Accepted: 03/26/2019] [Indexed: 11/18/2022]
Abstract
Amino acid fermentation is one of the major pillars of industrial biotechnology. The multi-billion USD amino acid market is rising steadily and is diversifying. Metabolic engineering is no longer focused solely on strain development for the bulk amino acids L-glutamate and L-lysine that are produced at the million-ton scale, but targets specialty amino acids. These demands are met by the development and application of new metabolic engineering tools including CRISPR and biosensor technologies as well as production processes by enabling a flexible feedstock concept, co-production and co-cultivation schemes. Metabolic engineering advances are exemplified for specialty proteinogenic amino acids, cyclic amino acids, omega-amino acids, and amino acids functionalized by hydroxylation, halogenation and N-methylation.
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Affiliation(s)
- Volker F Wendisch
- Genetics of Prokaryotes, Faculty of Biology and Center for Biotechnology (CeBiTec), Bielefeld University, Bielefeld, Germany.
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Costless metabolic secretions as drivers of interspecies interactions in microbial ecosystems. Nat Commun 2019; 10:103. [PMID: 30626871 PMCID: PMC6327061 DOI: 10.1038/s41467-018-07946-9] [Citation(s) in RCA: 153] [Impact Index Per Article: 30.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2018] [Accepted: 12/06/2018] [Indexed: 01/21/2023] Open
Abstract
Metabolic exchange mediates interactions among microbes, helping explain diversity in microbial communities. As these interactions often involve a fitness cost, it is unclear how stable cooperation can emerge. Here we use genome-scale metabolic models to investigate whether the release of “costless” metabolites (i.e. those that cause no fitness cost to the producer), can be a prominent driver of intermicrobial interactions. By performing over 2 million pairwise growth simulations of 24 species in a combinatorial assortment of environments, we identify a large space of metabolites that can be secreted without cost, thus generating ample cross-feeding opportunities. In addition to providing an atlas of putative interactions, we show that anoxic conditions can promote mutualisms by providing more opportunities for exchange of costless metabolites, resulting in an overrepresentation of stable ecological network motifs. These results may help identify interaction patterns in natural communities and inform the design of synthetic microbial consortia. In considering cross-feeding among microbes within communities, it is typically assumed that metabolic secretions are costly to produce. However, Pacheco et al. use metabolic models to show that ‘costless’ secretions could be common in some environments and important for structuring interactions among microbes.
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Microbial Production of l-Serine from Renewable Feedstocks. Trends Biotechnol 2018; 36:700-712. [DOI: 10.1016/j.tibtech.2018.02.001] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2017] [Revised: 01/30/2018] [Accepted: 02/01/2018] [Indexed: 11/21/2022]
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Tyulenev A, Smirnova G, Muzyka N, Ushakov V, Oktyabrsky O. The role of sulfides in stress-induced changes of Eh in Escherichia coli cultures. Bioelectrochemistry 2018; 121:11-17. [DOI: 10.1016/j.bioelechem.2017.12.012] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2017] [Revised: 12/06/2017] [Accepted: 12/22/2017] [Indexed: 11/25/2022]
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Pinu FR, Granucci N, Daniell J, Han TL, Carneiro S, Rocha I, Nielsen J, Villas-Boas SG. Metabolite secretion in microorganisms: the theory of metabolic overflow put to the test. Metabolomics 2018; 14:43. [PMID: 30830324 DOI: 10.1007/s11306-018-1339-7] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/10/2017] [Accepted: 02/07/2018] [Indexed: 12/24/2022]
Abstract
INTRODUCTION Microbial cells secrete many metabolites during growth, including important intermediates of the central carbon metabolism. This has not been taken into account by researchers when modeling microbial metabolism for metabolic engineering and systems biology studies. MATERIALS AND METHODS The uptake of metabolites by microorganisms is well studied, but our knowledge of how and why they secrete different intracellular compounds is poor. The secretion of metabolites by microbial cells has traditionally been regarded as a consequence of intracellular metabolic overflow. CONCLUSIONS Here, we provide evidence based on time-series metabolomics data that microbial cells eliminate some metabolites in response to environmental cues, independent of metabolic overflow. Moreover, we review the different mechanisms of metabolite secretion and explore how this knowledge can benefit metabolic modeling and engineering.
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Affiliation(s)
- Farhana R Pinu
- The New Zealand Institute for Plant and Food Research Limited, Private Bag 92169, Auckland, 1142, New Zealand.
| | - Ninna Granucci
- School of Biological Sciences, University of Auckland, Private Bag 92019, Auckland, New Zealand
| | - James Daniell
- School of Biological Sciences, University of Auckland, Private Bag 92019, Auckland, New Zealand
- LanzaTech, Skokie, IL, 60077, USA
| | - Ting-Li Han
- School of Biological Sciences, University of Auckland, Private Bag 92019, Auckland, New Zealand
| | - Sonia Carneiro
- Center of Biological Engineering, University of Minho, Campus de Gualtar, 4710-057, Braga, Portugal
| | - Isabel Rocha
- Center of Biological Engineering, University of Minho, Campus de Gualtar, 4710-057, Braga, Portugal
| | - Jens Nielsen
- Department of Biology and Biological Engineering, Chalmers University of Technology, Kemivagen 10, 412 96, Gothenburg, Sweden
- Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, 2970, Hørsholm, Denmark
| | - Silas G Villas-Boas
- School of Biological Sciences, University of Auckland, Private Bag 92019, Auckland, New Zealand
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Liu H, Fang G, Wu H, Li Z, Ye Q. L-Cysteine Production in Escherichia coli Based on Rational Metabolic Engineering and Modular Strategy. Biotechnol J 2018; 13:e1700695. [PMID: 29405609 DOI: 10.1002/biot.201700695] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2017] [Revised: 01/25/2018] [Indexed: 01/07/2023]
Abstract
L-cysteine is an amino acid with important physiological functions and has a wide range of applications in medicine, food, animal feed, and cosmetics industry. In this study, the L-cysteine synthesis in Escherichia coliEscherichia coli is divided into four modules: the transport module, sulfur module, precursor module, and degradation module. The engineered strain LH03 (overexpression of the feedback-insensitive cysE and the exporter ydeD in JM109) accumulated 45.8 mg L-1 of L-cysteine in 48 hr with yield of 0.4% g/g glucose. Further modifications of strains and culture conditions which based on the rational metabolic engineering and modular strategy improved the L-cysteine biosynthesis significantly. The engineered strain LH06 (with additional overexpression of serA, serC, and serB and double mutant of tnaA and sdaA in LH03) produced 620.9 mg L-1 of L-cysteine with yield of 6.0% g/g glucose, which increased the production by 12 times and the yield by 14 times more than those of LH03 in the original condition. In fed-batch fermentation performed in a 5-L reactor, the concentration of L-cysteine achieved 5.1 g L-1 in 32 hr. This work demonstrates that the combination of rational metabolic engineering and module strategy is a promising approach for increasing the L-cysteine production in E. coli.
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Affiliation(s)
- Han Liu
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai 200237, China
| | - Guochen Fang
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai 200237, China
| | - Hui Wu
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai 200237, China.,Shanghai Collaborative Innovation Center for Biomanufacturing Technology, 130 Meilong Road, Shanghai 200237, China.,Key Laboratory of Bio-based Material Engineering of China National Light Industry Council, 130 Meilong Road, Shanghai 200237, China
| | - Zhimin Li
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai 200237, China.,Shanghai Collaborative Innovation Center for Biomanufacturing Technology, 130 Meilong Road, Shanghai 200237, China
| | - Qin Ye
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai 200237, China
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Nonaka G, Takumi K. Cysteine degradation gene yhaM, encoding cysteine desulfidase, serves as a genetic engineering target to improve cysteine production in Escherichia coli. AMB Express 2017; 7:90. [PMID: 28488255 PMCID: PMC5423876 DOI: 10.1186/s13568-017-0389-y] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2017] [Accepted: 04/21/2017] [Indexed: 11/16/2022] Open
Abstract
Cysteine is an important amino acid for various industries; however, there is no efficient microbial fermentation-based production method available. Owing to its cytotoxicity, bacterial intracellular levels of cysteine are stringently controlled via several modes of regulation, including cysteine degradation by cysteine desulfhydrases and cysteine desulfidases. In Escherichia coli, several metabolic enzymes are known to exhibit cysteine degradative activities, however, their specificity and physiological significance for cysteine detoxification via degradation are unclear. Relaxing the strict regulation of cysteine is crucial for its overproduction; therefore, identifying and modulating the major degradative activity could facilitate the genetic engineering of a cysteine-producing strain. In the present study, we used genetic screening to identify genes that confer cysteine resistance in E. coli and we identified yhaM, which encodes cysteine desulfidase and decomposes cysteine into hydrogen sulfide, pyruvate, and ammonium. Phenotypic characterization of a yhaM mutant via growth under toxic concentrations of cysteine followed by transcriptional analysis of its response to cysteine showed that yhaM is cysteine-inducible, and its physiological role is associated with resisting the deleterious effects of cysteine in E. coli. In addition, we confirmed the effects of this gene on the fermentative production of cysteine using E. coli-based cysteine-producing strains. We propose that yhaM encodes the major cysteine-degrading enzyme and it has the most significant role in cysteine detoxification among the numerous enzymes reported in E. coli, thereby providing a core target for genetic engineering to improve cysteine production in this bacterium.
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Anaerobic Cysteine Degradation and Potential Metabolic Coordination in Salmonella enterica and Escherichia coli. J Bacteriol 2017; 199:JB.00117-17. [PMID: 28607157 DOI: 10.1128/jb.00117-17] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2017] [Accepted: 06/02/2017] [Indexed: 01/12/2023] Open
Abstract
Salmonella enterica has two CyuR-activated enzymes that degrade cysteine, i.e., the aerobic CdsH and an unidentified anaerobic enzyme; Escherichia coli has only the latter. To identify the anaerobic enzyme, transcript profiling was performed for E. coli without cyuR and with overexpressed cyuR Thirty-seven genes showed at least 5-fold changes in expression, and the cyuPA (formerly yhaOM) operon showed the greatest difference. Homology suggested that CyuP and CyuA represent a cysteine transporter and an iron-sulfur-containing cysteine desulfidase, respectively. E. coli and S. enterica ΔcyuA mutants grown with cysteine generated substantially less sulfide and had lower growth yields. Oxygen affected the CyuR-dependent genes reciprocally; cyuP-lacZ expression was greater anaerobically, whereas cdsH-lacZ expression was greater aerobically. In E. coli and S. enterica, anaerobic cyuP expression required cyuR and cysteine and was induced by l-cysteine, d-cysteine, and a few sulfur-containing compounds. Loss of either CyuA or RidA, both of which contribute to cysteine degradation to pyruvate, increased cyuP-lacZ expression, which suggests that CyuA modulates intracellular cysteine concentrations. Phylogenetic analysis showed that CyuA homologs are present in obligate and facultative anaerobes, confirming an anaerobic function, and in archaeal methanogens and bacterial acetogens, suggesting an ancient origin. Our results show that CyuA is the major anaerobic cysteine-catabolizing enzyme in both E. coli and S. enterica, and it is proposed that anaerobic cysteine catabolism can contribute to coordination of sulfur assimilation and amino acid synthesis.IMPORTANCE Sulfur-containing compounds such as cysteine and sulfide are essential and reactive metabolites. Exogenous sulfur-containing compounds can alter the thiol landscape and intracellular redox reactions and are known to affect several cellular processes, including swarming motility, antibiotic sensitivity, and biofilm formation. Cysteine inhibits several enzymes of amino acid synthesis; therefore, increasing cysteine concentrations could increase the levels of the inhibited enzymes. This inhibition implies that control of intracellular cysteine levels, which is the immediate product of sulfide assimilation, can affect several pathways and coordinate metabolism. For these and other reasons, cysteine and sulfide concentrations must be controlled, and this work shows that cysteine catabolism contributes to this control.
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Fermentative Production of Cysteine by Pantoea ananatis. Appl Environ Microbiol 2017; 83:AEM.02502-16. [PMID: 28003193 DOI: 10.1128/aem.02502-16] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2016] [Accepted: 12/15/2016] [Indexed: 11/20/2022] Open
Abstract
Cysteine is a commercially important amino acid; however, it lacks an efficient fermentative production method. Due to its cytotoxicity, intracellular cysteine levels are stringently controlled via several regulatory modes. Managing its toxic effects as well as understanding and deregulating the complexities of regulation are crucial for establishing the fermentative production of cysteine. The regulatory modes include feedback inhibition of key metabolic enzymes, degradation, efflux pumps, and the transcriptional regulation of biosynthetic genes by a master cysteine regulator, CysB. These processes have been extensively studied using Escherichia coli for overproducing cysteine by fermentation. In this study, we genetically engineered Pantoea ananatis, an emerging host for the fermentative production of bio-based materials, to identify key factors required for cysteine production. According to this and our previous studies, we identified a major cysteine desulfhydrase gene, ccdA (formerly PAJ_0331), involved in cysteine degradation, and the cysteine efflux pump genes cefA and cefB (formerly PAJ_3026 and PAJ_p0018, respectively), which may be responsible for downregulating the intracellular cysteine level. Our findings revealed that ccdA deletion and cefA and cefB overexpression are crucial factors for establishing fermentative cysteine production in P. ananatis and for obtaining a higher cysteine yield when combined with genes in the cysteine biosynthetic pathway. To our knowledge, this is the first demonstration of cysteine production in P. ananatis, which has fundamental implications for establishing overproduction in this microbe.IMPORTANCE The efficient production of cysteine is a major challenge in the amino acid fermentation industry. In this study, we identified cysteine efflux pumps and degradation pathways as essential elements and genetically engineered Pantoea ananatis, an emerging host for the fermentative production of bio-based materials, to establish the fermentative production of cysteine. This study provides crucial insights into the design and construction of cysteine-producing strains, which may play central roles in realizing commercial basis production.
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